Tutors Answer Your Questions about Exponential-and-logarithmic-functions (FREE)
Question 433710: There are currently 60 million cars in a certain country, decreasing by 5% annually. How many years will it take for this country to have 34 million cars?
A) 65 years B) 5 years C) 11 years D) 2 years
Thank you for your help.
Click here to see answer by rwm(914)  |
Question 433782: Suppose that you are a mathematician for Well Oils Production ,Inc. Your company is planning to drill a well 50,000 feet deep,deeper than anyone has ever drilled before.Your part of the project is to predict the cost of drilling the well. From previous well records,you ascertain that the price is 20$ per foot for drilling at the surface. and #30 per foot for drilling at 10,00 feet. Assume that the number of dollars per foot for drilling an oil well increases exponentially with the depth at which the drill is operating.
a. White equation expressing price per foot in terms of depth. You might find it more convenient to express depth in thousands of feet.
b. Predict the price per foot for drilling at depth of 20,30,40 and 50 thousand feet.
c. Carefully plot the graph of the price per foot versus depth. Choose scales that make the graph occupy most of the piece of the graph paper.
d. The area of the region under the graph represents the total number of dollars it costs to drill the well. You can see the reason by considering the units of this area. The vertical distance is $/ft and the horizontal distance is ft.,so the area has units A=(dollars/foot)*feet, or simply dollars. Count the number of squares in this region on your graph. Estimate fractional squares to the nearest 0.1 unit. When you study calculus, you will learn how to calculate such areas from the equation without having to count squares.
e. calculate the number of dollars corresponding to each square. For example, if the horizontal spacing is 2000 feet, and the vertical spacing is 5$/ft, then each square corresponds to (2000)(5)=$10000
f. Calculate the total cost of drilling the well.
Click here to see answer by psbhowmick(878)  |
Question 434663: I am having difficulty with this logarithmic equation. I have completed many problems like it, but this one eludes me.
4^(x+3) = 3^(-x)
Could someone help me with this problem. Maybe some example problems would help. Thank you.
Click here to see answer by Alan3354(69443)  |
Question 434828: how can i find when the co2 ppm will double the preindustrial age of 280ppm
with 2000 being x=0 2001 is = to 1 and so on untill 2200
in the year 2000 co2 ppm 364 and 2050 is 467 and 2100 is 600ppm, 2150 is 769 and 2200 is 987
with F(x)= Ca^x
Click here to see answer by stanbon(75887) |
Question 434856: suppose that a certain radioactive substance has a half life of 20 years. if there is presently 2500 milligrams of the substance, how much, to the nearest milligram will remain after 40 years? after 50 years?
Click here to see answer by stanbon(75887) |
Question 435260: the graph of f(x) shown below, resembles the graph of g(x)=x^2, but it has been flipped over the x-axis and shifted down 4 units and left 1 unit. write the equation of f(x).
step1: using the equation f(x)=x^2, write the equaton for the groah that has been flipped over the x-axis.
step2: using the equation written in step 1, write the equation for the graph that has also been shifted down 4 units.
step3:using the equation written in step 2, write the equation for the graph that has also been shifted left 1 units.
Click here to see answer by ewatrrr(24785)  |
Question 436406: find the number of years it would take to grow an initial investment of $2,000 to a future value of $5,000, at an interest rate of 8.5%, compounded annually.
formula: FVn=PV(1+i)n
FVn IS THE FUTURE VALUE OF THE INVESTMENT AFTER N YEARS
PV IS THE INITIAL AMOUNT OF THE INVESTMENT
i is the interest rate
n is the length of the investment in years
Click here to see answer by rfer(16322) |
Question 436406: find the number of years it would take to grow an initial investment of $2,000 to a future value of $5,000, at an interest rate of 8.5%, compounded annually.
formula: FVn=PV(1+i)n
FVn IS THE FUTURE VALUE OF THE INVESTMENT AFTER N YEARS
PV IS THE INITIAL AMOUNT OF THE INVESTMENT
i is the interest rate
n is the length of the investment in years
Click here to see answer by mananth(16946)  |
Question 436617: Im not sure if this is the right section, but if anyone can help me with the following types of problems I would greatly appreciate. I just realized I have the wrong text, and there are no examples!! Thank you!
Find the following limit:
lim
x -> 3
2x^2-9x+2
Find the following limit:
lim
x -> 2
2x-1/3x+4
The equation part should be directly across from the lim, however this application makes that impossible. Thanks!!
Click here to see answer by richard1234(7193)  |
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