answered 2/2/2010 How You Solve Sin X = Tan X? Tanx=sinx sinx/cosx=sinx sinx=sinx*cosx 0=sinx*cosx-sinx 0=sinx(cosx-1) sinx=0 cosx=1 x1=k*pi x2=2*k*pi ; k € IR x1 covers both so x=k*pi.