Find the exact value of: tan(-3pi).

Answer 1

very easy
remember that tanx = sinx/cosx

and that the sine curve has a zero for every multiple of 180º or every multiple of pi
Since -3pi is a multiple of pi, sin(-3pi) = 0
We know that the cosine cannot be zero at that same angle since the sine and cosine curves do not coincide

so tan(-3pi) = 0