Question

How do you find the exact value of tan^-1[tan(2pi/5)]?

Answer 1

`x=72^@,252^@,610^@,792^@. . . . . .`

Explanation:

Let

`tan^(-1)(tan((2pi)/5))=x` `" "color(green)((1))`

`=>tan((2pi)/5)=tan(x)`

`=>tan(72^@)=tan(x^@)` `" "color(green)((2))`

`" "color(green)((2))` satisfies for `x=72^@,252^@,610^@,792^@. . . . . .`