Question

Simplify the expression by using a double angle formula2 tan 18 degrees/ 1-tan^2 18 degrees

Answer 1

Given the expression:

`(2\tan18\degree)/(1-\tan^218\degree)`

Using the double angle formula for the tangent:

`\tan(2x)=(2\tan x)/(1-\tan^2x)`

Finally, we identify x = 18°:

`(2\tan18\degree)/(1-\tan^218\degree)=\tan36\degree`