Ask a New Question

Question

An exponential function "f" is defined by f(x)=7(1.5)^x-6. if f(k)=91, then what is the value of k?
15 years ago

Answers

Reiny
you are solving

7(1.5)^(k-6) = 91
1.5^(k-6) = 13

take log of both sides
log [1.5^(k-6)] = log 13
(k-6)[log 1.5] = log 13
k-6 = log13/log1.5 = 6.3259
k = 12.3259

check
7(1.5^6.3259)
= 7(12.99977) = 90.9984 (not bad)
15 years ago
sam
log1/7(x^2=x)-log1/7(x^2-x)=-1
10 years ago

Related Questions

Which exponential function can be used to show the geometric sequence 40, 160, 640, ...? a. an=4(40... Which exponential function can be used to show the geometric sequence 40, 160, 640, ...? (1 point)... An exponential function is described by the equation h(x)=49(27)x . Which inequality describes t... An exponential function has the equation f(x)=−3^x−2 . Complete the inequality to show the range... An exponential function has the equation f(x)=−3^x−2 . Complete the inequality to show the range... An exponential function f(x)=(25)x 𝑓 ( 𝑥 ) = ( 2 5 ) 𝑥 contains the point (3,0.064) (... If the exponential function f(x)=9x includes the point (2,81) on the graph of the exponential cu... If the exponential function f(x)=7x includes the point (2,49) on the graph of the exponential curve,...
Ask a New Question
Archives Contact Us Privacy Policy Terms of Use