Question

find the algebraic expression of cos(tan^-1 x)

Answer 1

To do these types of problems always go with that inside inverse function and call it something like u
And then build a right triangle off that information u gives you.
Then find cos(u)

Answer 2

\[u=\tan^{-1}(x)\]
\[\tan(u)=x (=\frac{x}{1}=\frac{opp}{adj})\]

Answer 3

Make a right triangle off that information.

Answer 4

Thank you!!

Answer 5

Did you want to make a right triangle off that information and I look at your work...
Or are you saying you got it from here?