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anonymous
 one year ago
Given the function f(x) = 0.5(3)x, what is the value of f−1(7)?
anonymous
 one year ago
Given the function f(x) = 0.5(3)x, what is the value of f−1(7)?

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anonymous
 one year ago
Best ResponseYou've already chosen the best response.0sO far, i have x=0.5(3)y

mathstudent55
 one year ago
Best ResponseYou've already chosen the best response.3\(\Large f(x) = (0.5 ) 3^x\) \(\Large 7 = (0.5)3^x\) Solve for x.

mathstudent55
 one year ago
Best ResponseYou've already chosen the best response.3No. You can't multiply 0.5 by 3 since 3 is raised to x. What you can do is divide both sides by 0.5. Then take log of both sides.

mathstudent55
 one year ago
Best ResponseYou've already chosen the best response.3Look at this example. See why you can't multiply the 0.5 and the 3 together because of the exponent. dw:1439224190773:dw

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Oh! Yes, I understand noe :)

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Going back to #1, I got 1.140 as answer.

mathstudent55
 one year ago
Best ResponseYou've already chosen the best response.3\(\Large 7 = (0.5)3^x\) \(\Large \dfrac{7}{0.5} = \dfrac{(0.5)3^x}{0.5} \) \(\Large 14 = 3^x\) Now take log of both sides.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0well log(14)=1.14612803568 and log(3)=0.47712125472

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0So then you divide??

mathstudent55
 one year ago
Best ResponseYou've already chosen the best response.3I prefer to keep the answer exact, and not use decimal approximations. We take log of both sides: \(\Large \log 14 = \log 3^x\) \(\Large \log 14 = x \log 3\) Divide both sides by log 3: \(\Large \dfrac{\log 14}{\log 3} = x\) \(\Large x = \dfrac{\log 14}{\log 3} \)

mathstudent55
 one year ago
Best ResponseYou've already chosen the best response.3That is fine if you are allowed to give an approximate answer. If you need an exact answer, then it's the fraction of logs above.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Ok:) Thanks! Can I ask one more?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Given the parent functions f(x) = log2 (3x − 9) and g(x) = log2 (x − 3), what is f(x) − g(x)?

mathstudent55
 one year ago
Best ResponseYou've already chosen the best response.3Subtract the functions. \(\Large f(x) = \log_2 (3x  9) \) \(\Large g(x) = \log_2(x  3)\) We subtract the second equation from the first equation: \(\Large f(x)  g(x) = \log_2(3x  9)  \log_2(x  3) \) Ok so far?

mathstudent55
 one year ago
Best ResponseYou've already chosen the best response.3We're not done yet, but do you understand what we did so far?
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