Question

How do you find the value for `tan[tan^-1(7.4)]`?

Answer 1

By definition `tan(tan^-1(7.4)) = 7.4`

More explicitly:

Let `alpha = tan^-1(7.4)`

Then by definition `alpha` is the unique angle such that `tan alpha = 7.4` and `-pi/2 < alpha < pi/2`.