Exponential Functions?!
posted by Tabby on .
solve 9^(2x3) > 4. Round your answer to the nearest hundredth.
The part in parenthesis is up at top like an exponent. I dont' know how to do this. Please help me.

find the value of x such that
9^(2x3) = 4
ln both sides
(2x3) ln9 = ln4
2x3 = ln4/log9
2x = 3 + ln4/ln9
x = (3 + ln4/ln9)/2 = appr 1.82
so x > 1.82
check:
let x = 1.81
LS = 9^(.62) = 3.905..... < 4
let x = 1.83
LS = 9^(.66) = 4.26.. > 4 
Ah, thank you so much!!! GOd bless you!