Question

How do you prove that tangent is an odd function?

Answer 1

A function is even if:

`f(-x)=f(x)`.

A function is odd if:

`f(-x)=-f(x)`.

In this case:
`y=tan(-x)=sin(-x)/cos(-x)=(-sin(x))/cosx=-sinx/cosx=-tan(x)`,

for the simmetry of sinus and cosinus.