Question

is there any relation between sin and cos

Answer 1

 1) Sin X = O/H
     Cos X = A/H
     Hence , sinx/cosx = (O/H)/(A/H)
           = Tan X 

2) Sin^2 + Cos^2 = O^2/H^2 + A^2/H^2
                        
     ( O^2 + A^2 = H^2 ...By pythagoras theoram )

      H^2 / H^2 = 1

Hope it helps u ... ^_^