Question

Suppose tanΘ = 3/5 , and that Θ is in quadrant I. Find tan2Θ.

Answer 1

tan 2 O  =    2 tan O / (1 - tan^2 O)

   = 3/5 / (1 - (3/5)^2)

  =  3/5  *  25/16  =  15/16  Answer