Question

How do you find the indefinite integral of `int 5^-x`?

Answer 1

`because, inta^xdx=a^x/lna+c, :. int5^-xdx=int(1/5)^xdx`

`=(1/5)^x/ln(1/5)=(5^-x)/(ln1-ln5)=-5^-x/ln5+C.`