Integrate 9^x

Integrate 9^x

To integrate 9^x, also written as ∫ 9x dx, we first recognise that this is an exponential and will require the base change technique.

Changing the base technique.

At this step, we change the base as shown above.

Taking logs on both sides.

We take log to the base e on both sides.

simplifying

At this step, we find that lne=1, which simplifies the above expression.

Expression for z

We now have an expression for z.

substitution of z.

We substitute for z in the expression 9^x=e^z to give the above expression.

Integrating the easier version.

As you can see, we now have a simpler integration, which is the same thing.

answer.

We integrate the simpler version, where C is the integration constant.

Using substitution to simplify.

Since e^xln9=9^x, which we found earlier, we can substitute that to give the above expression.

Final Answer - Top Marks!

Finally, this is the result.