Tutors Answer Your Questions about Exponential-and-logarithmic-functions (FREE)
Question 275109: I can do some of this problem, except for the very last part.
Solve: 3e^4x+7=9. I get all the way down to the part where you have to divide by 4 and can't get the correct answer. The answer is x=-1.4753
How do I divide this using the TI-84
4x over 4 cancels out to be just x. But the ln 3-7 divided by 4. I cannot figure out how to enter it in the calculator. I have tried every way possible and it is not working. Thanks
Click here to see answer by nerdybill(7384)   |
Question 275383: Find the number of years it will take for $31,000 to grow to 33,405.06 at 3% interest compounded quarterly. I am going wrong somwhere toward the end of the problem. We have to use the graphing calculator. We don't have to graph it, but just use the calculator to find the answer. I get all the way down to the end. Where it will ask to solve for t. It comes down to
log(1.08)/4log(1.0075)=t
I entered it in the calculator exactly like this log(1.08)/4log(1.0075) My answer comes out to 2.711547965E-5. It says round to the nearest tenth and when I put down 2.7 I got it wrong. It came out to 2.5. Where could I be going wrong? Thanks....
PS: Also how do I thank a tutor for their help? I can't find how to leave feedback.
Click here to see answer by scott8148(6628)  |
Question 275383: Find the number of years it will take for $31,000 to grow to 33,405.06 at 3% interest compounded quarterly. I am going wrong somwhere toward the end of the problem. We have to use the graphing calculator. We don't have to graph it, but just use the calculator to find the answer. I get all the way down to the end. Where it will ask to solve for t. It comes down to
log(1.08)/4log(1.0075)=t
I entered it in the calculator exactly like this log(1.08)/4log(1.0075) My answer comes out to 2.711547965E-5. It says round to the nearest tenth and when I put down 2.7 I got it wrong. It came out to 2.5. Where could I be going wrong? Thanks....
PS: Also how do I thank a tutor for their help? I can't find how to leave feedback.
Click here to see answer by ankor@dixie-net.com(22740)  |
Question 275518: When x = 2 and y = 3, z = 42. Write the function that models each of the following relationships.
1. z varies inversely with x and directly with y. (1 point)
2. z varies jointly with x and y (1 point)
3. z varies directly with x and inversely with the square of y (1 point)
Click here to see answer by Theo(13342)  |
Question 275924: I am going to try to write this question so that it is easy to understand...I hope. I am writing it out, as I am not real sure how to write it using a formula that may be available through this site. I have tried several times and cannot get the correct answer. I don't understand how to get the final answer. Such as 1/x or 1/x^2 and so on.
It says: Use the properties of the logarithms to write the expression as one logarithm. I can't find what property has anything to do with the square root symbol. That is the part that mainly confuses me.
4 log base 4 2(SQRT(x) - 3 log base of 4 x. It is a square root with a 2 in the index and an x underneath. Thanks in advance if anyone can explain this.
Click here to see answer by jsmallt9(3758) |
Question 276236: use the exponential growth function, P(t)=Poe^kt, to find the value of k, then write the write the function for this population as a function of time, t.
1984= 746,388,000 1974=574,220,000 t=0 1974 t=10 1984
Click here to see answer by jsmallt9(3758) |
Question 276286: Solve Equation
log5(3x-1)=1 I can't figure this one out, any help would be appreciated!!
log x+log(x-3)=1 I solved this one but wanted to make sure I'm doing this correct
log(x(x+3))=1
x(x+3)=10^1=10
x^2+3x=10
x^2+3x-10=0
(x+5)(x-2)=0
x=-5, 2
Click here to see answer by jsmallt9(3758) |
Question 276564: The lens equation for a camera is 1/f= 1/di+1/d0, where f is the focal length of the lens, di is the distance between the lens and the film, and d0 is the distance between the lens and the object. For a certain camera, an object that is 18 cm from the lens is in focus when the lens is 9 cm from the film. What is the focal length of the lens?
this is what i worked it out too-> 1/f= 4/9
Click here to see answer by jsmallt9(3758) |
Question 276809: *URGENT*
use the exponential growth function, P(t)=Poe^kt, to find the value of k, then write the write the function for this population as a function of time, t.
Use the function to presict the population in 2005 if it continues to decline at the same rate.
1984= 746,388,000 1974=574,220,000 t=0 1974 t=10 1984
The answer has to be 15,531
Click here to see answer by jsmallt9(3758) |
Question 277085: Two standard number cubes are tossed. State whether the events are mutually exclusive by answering with yes or no.
4. The product is greater than 6; the sum is less than 7.
[i think its yes]
5. The sum is odd; the product is odd.
[i think its no]
Click here to see answer by jsmallt9(3758) |
Question 276907: Please help.
Find the equation of the following in the form y=ab^x. Be sure to check the x-increments when finding b. (?)
I was given these tables:
a) x:1,2,3,4
y:3,6,12,24
b) x:4,8,12,16
y:2,2/3,2/9,2/27
c)x:1,2,3,4
y:0.75,2.25,6.75,20.25
Click here to see answer by jsmallt9(3758) |
Question 277306: Find an exponential function of the form P(t)=Yoe^(kt) to model given
In 1985, the number of female athletes participating in summer Olympic type games was 450. In 1996 about 3650 participated in the summer Olympics. Assuming p(0)=450. find the value to the hundredths place.
Click here to see answer by stanbon(75887) |
Question 277610: Radioactive iodine treatment is so successful at treating hyperthyroidism that it has virtually replaced thyroid surgery. To the nearest full day, determine how long it will take for 400 millicuries of I-131, which has a half-life of 8 days, to decay to 3.125 millicuries.
Click here to see answer by ankor@dixie-net.com(22740) |
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