Verified answer

cos(90-x) =cos90°*cos x+sen 90°*sen x =0*cos x +1*sen x =sen x (1)

cotg (90°-x) =1+cotg90°*cotg x /cotgx-cotg90 =1+0*cotg x/cotgx -0 =1/cotg x =tg x (2)

sen(360°-x)=sen360*cos x-sen x*cos360 =0 -sen x *1 =-sen x (3)

fazendo o produto 1*3*2 =>>> sen x * tg x *-sen x =senx *-senx *tg x >>>

-sen²x *senx/cosx =-sen³x /cosx ////