How do you find the derivative of #f(x)= 1/(9x+6)^2#?
1 Answer
Feb 22, 2016
Explanation:
Since this is under the chain rule, then use it.
Substitute
#frac{"d"u}{"d"x} = 9#
So plug it in.
#f'(x) = frac{"d"}{"d"x}(1/(9x + 6)^2)#
#= frac{"d"}{"d"x}(1/u^2)#
#= frac{"d"}{"d"u}(u^{-2})*frac{"d"u}{"d"x}#
#= (-2) * u^{-3} * (9)#
#= -18 / (9x + 6)^{3}#
#= -18 / (3^3*(3x + 2)^{3})#
#= -2 / (3*(3x + 2)^{3})#
