math
posted by bobby on .
Let
f(x) = (7^(x))* (log base 3 of(x))
f '(x) =

you just need to memorize a couple more formulas:
you know that if
f = e^x
f' = e^x
f = a^x
f' = a^x ln(a)
log_{b}x = ln(x)/ln(b)
f = log_{b}x
f' = 1/ln(b) * 1/x
so, for f above,
f' = 7^x ln7 log_{3}x + 7^x * 1/xln3
= 7^x ln7 lnx/ln3 + 7^x *1/xln3
= 7^x/xln3 (x ln7 lnx + 1)