Question

How do you find the derivative of `y=4^(-x)`?

Answer 1

`dy/dx= -ln4*4^-x`

Explanation:

`y = 4^-x`

`lny = -x*ln4`

`1/y dy/dx= -ln4`
[Implicit differentiation, standard diferential and power rule]

`dy/dx= -ln4 *y`

`= -ln4*4^-x`