Business Calculus Review
(1) If a sum of money
is invested for a time period
(in years) at an interest rate
per period, the simple interest is given by
Solving for
we have,
(a)
(b)
(c)
(d)
(e)
![business calculus review _gr_10.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_10.gif)
(2) Given
, the value of
is
(a) 6 (b)
(c)
(d)
(e) not enough information
(3) What is the present value of an investment at 6% annual simple interest if it is worth 832 dollars in 8 months?
(a)
(b)
(c)
(d)
(e) none of the above
(4) Solve for
with
![business calculus review _gr_21.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_21.gif)
(a)
(b)
(c)
(d)
(e) no solution
(5) Most people who are retiring purchase an annuity to supplement their income.
This annuity pays them a fixed sum of money at regular intervals.
The single sum of money required to purchase an annuity that will provide these payments is called the
(a) principal (b) down payment (c) annual percentage yield (d) future value (e) present value
(6) The function defined by
is an exponential growth function.
(a) True, because
(b) False, because
![business calculus review _gr_28.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_28.gif) (c) False (d) True, because
![business calculus review _gr_29.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_29.gif) (e) none of the above
(7) Suppose a couple is saving for a future purchase by making periodic payments to produce a future sum on a specified date.
This type of investment is called a
(a) simple interest (b) decay function (c) sinking fund (d) loan (e) amortization
(8) Suppose 100,000 dollars is invested for 10 years at 8% compounded quarterly.
For the equation,
, the present value is given by
(a)
(b)
(c)
(d)
(e) none of the above
(9) If 10,000 dollars is invested at 1% per month, the future value
at any time
(in months) is given by
How long before the investment doubles?
(10) Develop an amortization schedule for a loan of 30,000 dollars to be repaid in 4 annual payments of equal size.
The interest rate is 7%.
(11) Is it more economical to buy an automobile for 29,000 dollars in cash or to pay 8000 dollars down and 3000 dollars at the end of each quarter for 2 years, if money if worth 8% compounded quarterly?
Solution.
The automobile can be bought now for 29,000 dollars or can be bought for 8000 dollars plus the present value of the investment.
The present value is given by the formula
where
and
so we have
Thus the automobile can be bought for 29,000 dollars or for
dollars.
Thus, it is cheaper to pay cash.
(12) Given
determine
![business calculus review _gr_48.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_48.gif)
(a)
(b) does not exist (c)
(d)
(e) none of the above
Solution. Since
and
![business calculus review _gr_53.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_53.gif)
We see
The correct choice for is (c).
(13) Determine whether the function
is continuous at
![business calculus review _gr_57.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_57.gif)
(a) yes, because
(b) no, because
does not exist (c) no, because
does not exist.
(d) yes, because
![business calculus review _gr_61.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_61.gif) (e) none of the above
Solution. Since
but
so
is not continuous because
does not exist.
The correct choice is (c).
(14) Find the average rate of change of
over the interval
![business calculus review _gr_68.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_68.gif)
(a) 7 (b) 6.9 (c)
![business calculus review _gr_69.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_69.gif) (d) 6.8 (e) none of the above
Solution.
The average rate of change of
is
The correct choice is (b).
(15) Given the revenue function
(in dollars) where
denotes the number of units sold.
What is the marginal revenue if 50 units are sold?
(a) 290 (b) 12500 (c) 198 (d) 15198 (e) none of the above
Solution.
Since
we see the marginal revenue for
units sold is
The correct choice is (e).
(16) Find
given
![business calculus review _gr_80.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_80.gif)
(a)
![business calculus review _gr_81.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_81.gif) (b)
(c)
(d)
![business calculus review _gr_84.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_84.gif) (e) none of the above
Solution.
Using the power rule,
The correct choice is (b).
(17) Find
given
![business calculus review _gr_88.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_88.gif)
(a)
(b)
(c)
(d)
(e) none of the above
Solution.
Using the power rule
The correct choice is (d).
(18) Find an equation of the tangent line to the graph of the function
at
![business calculus review _gr_96.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_96.gif)
(a)
![business calculus review _gr_97.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_97.gif) (b)
![business calculus review _gr_98.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_98.gif) (c)
![business calculus review _gr_99.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_99.gif) (d)
![business calculus review _gr_100.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_100.gif) (e) none of the above
Solution.
First
and when
When
we find
Therefore, an equation of the tangent line is
which simplifies to
The correct choice is (d).
(19) Find
given
![business calculus review _gr_110.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_110.gif)
(a)
![business calculus review _gr_111.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_111.gif) (b)
![business calculus review _gr_112.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_112.gif) (c)
![business calculus review _gr_113.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_113.gif) (d)
![business calculus review _gr_114.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_114.gif) (e) none of the above
Solution.
Using the quotient rule
The correct choice is (a).
(20) Find
given
![business calculus review _gr_118.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_118.gif)
(a)
(b)
(c)
(d)
(e) none of the above
Solution.
Using the chain rule,
![business calculus review _gr_123.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_123.gif)
The correct choice is (d).
(21) Given the derivative
of a function
the second derivative test concludes that
(a)
and so
is a relative minium point. (b)
and so
is a relative minium point. (c)
and so
is a relative maximum point. (d)
and so
is a relative maximum point. (e) none of the above
Solution.
Since
and so
which means
is a relative minium point.
The correct choice is (b).
(22) Find
if
![business calculus review _gr_140.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_140.gif)
(a)
(b)
(c)
(d)
(e) none of the above
Solution.
We find
and so
The correct choice is (d).
(23) Determine the intervals where the graph of the function
is increasing given the first derivative of
as
![business calculus review _gr_150.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_150.gif)
(a)
and
(b)
and
(c)
(d)
(e) none of the above
Solution.
![business calculus review _gr_158.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_158.gif)
The correct choice is (a).
(24) Determine where the relative maximum occur for the function
whose first derivative is given as
(a) at
![business calculus review _gr_162.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_162.gif) (b) at
(c) at
(d) there are no relative maximum for the function
![business calculus review _gr_165.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_165.gif) (e) none of the above
Solution.
![business calculus review _gr_166.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_166.gif)
The correct choice is (a).
(25) Assume that a function
has domain all real numbers and whose first and second derivatives are
and
respectively, determine where the points of inflection occur for the graph of the function
![business calculus review _gr_171.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_171.gif)
(a) no points of inflection (b) at
and at
(c) at
![business calculus review _gr_174.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_174.gif)
(d) at
and at
(e) none of the above
Solution.
![business calculus review _gr_177.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_177.gif)
Thus, the
and
is where the points of inflection occur.
The correct choice is (d).
(26) Assume that a function
has domain all real numbers and whose first and second derivatives are
and
respectively, determine the intervals where the graph of the function
is concave up.
(a)
(b)
and
(c)
and
(d)
and
(e) none of the above
Solution.
![business calculus review _gr_192.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_192.gif)
Thus,
and
are the intervals when the graph of
is concave up. The correct choice is (b).
(27) Given
the second derivative test
(a) concludes that
is a critical point of
![business calculus review _gr_199.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_199.gif) (b) concludes that
has a local maximum at
(c) concludes that
has a local minimum at
(d) is inconclusive for
(e) none of the above
Solution. Since
the critical numbers are
and
Also, since
and so
Thus the second derivative test is inconclusive for
The correct choice is (d).
(28) Given
then
![business calculus review _gr_213.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_213.gif)
(a)
(b)
(c)
(d)
(e) none of the above
Solution. By definition,
The correct choice is (a).
(29) Determine
given
![business calculus review _gr_221.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_221.gif)
(a)
(b)
(c)
(d)
(e) none of the above
Solution.
Using the quotient rule the derivative of
is
The correct choice is (e).
(30) Determine
given
![business calculus review _gr_230.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_230.gif)
(a)
(b)
(c)
(d)
(e) none of the above
Solution.
Using the chain rule, the derivative of
is
![business calculus review _gr_236.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_236.gif)
![business calculus review _gr_237.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_237.gif)
The correct choice is (c).
(31) The average rate of change of
over the interval
is
(a)
(b)
(c)
(d)
(e) none of the above
Solution.
The average rate of change of
over the interval
is
so, the average rate of change of
over
is
![business calculus review _gr_250.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_250.gif)
The correct choice is (d).
(32) The marginal revenue of
at
is
(a)
(b)
(c)
![business calculus review _gr_256.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_256.gif)
(d)
![business calculus review _gr_257.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_257.gif) (e) none of the above
Solution.
The marginal revenue of
at
is
and so at
we find the marginal revenue to be
The correct choice is (b).
(33) Find the equation of the tangent line to the graph of the function
when
for
(a)
(b)
(c)
(d)
(e) none of the above
Solution.
The slope of the tangent line is
because
and when
![business calculus review _gr_273.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_273.gif)
The point
is found by
Thus an equation of the tangent line is
, that is
The correct choice is (a).
(34) Find
when
![business calculus review _gr_281.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_281.gif)
(a)
(b)
(c)
(d)
(e) none of the above
Solution.
Using the power rule and chain rule to find,
![business calculus review _gr_286.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_286.gif)
The correct choice is (b).
(35) Suppose the domain of
is all real numbers except
and
then the critical numbers of
are
(a)
and
![business calculus review _gr_294.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_294.gif) (b)
and
only (c)
only (d) there are no critical points because the domain of
is not all real numbers (e) none of the above
Solution.
Since
and both
and
are defined we see both
and
are critical numbers.
However, even though
is where
is undefined, but
is also not defined for
so
is not a critical number for
The correct choice is (b).
(36) Assume the domain of a function
is all real numbers and
Apply the First Derivative Test to determine where the function
is decreasing.
(a) on the interval
![business calculus review _gr_314.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_314.gif) (b) on the intervals
and
![business calculus review _gr_316.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_316.gif) (c) on the interval
(d) on the intervals
and
(e) none of the above
Solution.
The critical numbers are
and
When
then
When
then
When
then
and when
then
Therefore,
is decreasing on the intervals
and
A sketch of a function
with this derivative,
![business calculus review _gr_334.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_334.gif)
The the correct choice is (b).
(37) Given
determine the intervals where
is concave up.
(a)
and
(b)
![business calculus review _gr_340.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_340.gif) (c)
(d)
and
(e) none of the above
Solution.
First
when
and
When
when
When
and so
is concave up on the intervals
and
The correct choice is (a).
(38) If the total profit, in thousands of dollars, for a product is given by
ESTIMATE the profit from the sale of the 16th unit using marginal profit.
(a)
(b) half a penny (c)
(d)
![business calculus review _gr_360.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_360.gif) (e) none of the above
Solution.
Since
and so
The units are thousands of dollars and so the correct choice is (d).
(39) Evaluate the definite integral
(a) 0 (b) 1 (c) 2 (d) 4 (e) none of the above
(40) Evaluate the definite integral
(a)
![business calculus review _gr_366.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_366.gif) (b)
(c)
![business calculus review _gr_368.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_368.gif) (d)
![business calculus review _gr_369.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_369.gif) (e) none of the above
(41) Find the value of the sum
![business calculus review _gr_370.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_370.gif)
(a) 51 (b) 10 (c) 55 (d)
![business calculus review _gr_371.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_371.gif) (e) none of the above
(42) Approximate the area under the curve by evaluating the function
at the left-hand endpoints of the subintervals from
to
using 4 subintervals.
(a) 10 (b) 11.25 (c)
![business calculus review _gr_375.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_375.gif) (d) 12 (e) none of the above
(43) Evaluate the integral
![business calculus review _gr_376.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_376.gif)
(a)
where
is a constant (b)
where
is a constant (c)
where
is a constant (d)
where
is a constant (e) none of the above
(44) Evaluate the integral
![business calculus review _gr_385.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_385.gif)
(a)
where
is a constant (b)
where
is a constant (c)
where
is a constant (d)
where
is a constant (e) none of the above
(45) Evaluate the integral
![business calculus review _gr_394.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_394.gif)
(a)
where
is a constant (b)
where
is a constant (c)
where
is a constant (d)
where
is a constant (e) none of the above
(46) Evaluate the integral
![business calculus review _gr_403.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_403.gif)
(a)
where
is a constant (b)
where
is a constant (c)
where
is a constant (d)
where
is a constant (e) none of the above
(47) Evaluate the integral
![business calculus review _gr_412.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_412.gif)
(a)
where
is a constant (b)
where
is a constant (c)
where
is a constant (d)
where
is a constant (e) none of the above
(48) If
where
is a constant then
![business calculus review _gr_423.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_423.gif)
(a)
(b)
![business calculus review _gr_425.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_425.gif) (c)
![business calculus review _gr_426.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_426.gif) (d)
![business calculus review _gr_427.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_427.gif) (e) none of the above
(49) Find the elasticity of the demand function
at
![business calculus review _gr_429.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_429.gif)
(a)
![business calculus review _gr_430.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_430.gif) (b)
![business calculus review _gr_431.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_431.gif) (c) 21 (d)
![business calculus review _gr_432.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_432.gif) (e) none of the above
(50) Suppose the demand function for a product is given by
How would revenue be affected by a price increase when
and
![business calculus review _gr_435.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_435.gif)
(a) A price increase will decrease the total revenue. (b) A price increase will increase the total revenue. (c) A price increase will not affect the total revenue. (d) not enough information (e) none of the above
(51) Find the derivative of
with respect to the variable
![business calculus review _gr_437.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_437.gif)
(a)
![business calculus review _gr_438.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_438.gif) (b)
![business calculus review _gr_439.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_439.gif) (c)
![business calculus review _gr_440.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_440.gif) (d)
![business calculus review _gr_441.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_441.gif) (e) none of the above
(52) Find the derivative of
with respect to the variable
![business calculus review _gr_443.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_443.gif)
(a)
![business calculus review _gr_444.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_444.gif) (b)
![business calculus review _gr_445.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_445.gif) (c)
![business calculus review _gr_446.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_446.gif) (d)
![business calculus review _gr_447.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_447.gif) (e) none of the above
(53) Find the equation of the tangent line to the graph of
at
![business calculus review _gr_449.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_449.gif)
(a)
![business calculus review _gr_450.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_450.gif) (b)
![business calculus review _gr_451.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_451.gif) (c)
![business calculus review _gr_452.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_452.gif) (d)
![business calculus review _gr_453.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_453.gif) (e) none of the above
(54) If possible, solve the equation
![business calculus review _gr_454.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_454.gif)
Solution.
Using properties of logarithms,
![business calculus review _gr_455.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_455.gif)
![business calculus review _gr_456.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_456.gif)
![business calculus review _gr_457.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_457.gif)
![business calculus review _gr_458.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_458.gif)
![business calculus review _gr_459.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_459.gif)
![business calculus review _gr_460.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_460.gif)
![business calculus review _gr_461.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_461.gif)
Since
is not defined when
there is no solution to the equation
(55) Simplify
![business calculus review _gr_466.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_466.gif)
Solution.
Using properties of logarithms,
![business calculus review _gr_467.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_467.gif)
![business calculus review _gr_468.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_468.gif)
![business calculus review _gr_469.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_469.gif)
![business calculus review _gr_470.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_470.gif)
Thus,
![business calculus review _gr_471.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_471.gif)
![business calculus review _gr_472.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_472.gif)
![business calculus review _gr_473.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_473.gif)
(56) A debt of 250000 dollars is amortized with 50 equal payments of .
If interest is 4.3%, compounded monthly, the unpaid balance of the debt after 30 payments have been made, approximate to the nearest dollar, is
(57) If 22,000 dollars is invested at 5.8%, compounded continuously, how long will it take the investment to grow to 500,000 dollars?
Solution.
By the meaning of compounded continuously
![business calculus review _gr_475.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_475.gif)
So we solve for
![business calculus review _gr_476.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_476.gif)
![business calculus review _gr_477.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_477.gif)
![business calculus review _gr_478.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_478.gif)
![business calculus review _gr_479.gif]](pages/business-calculus-review/Images/business-calculus-review_gr_479.gif)
years
|