Udowodnij tożsamość trygonometryczną: (tg x + 1)/(ctg x + 1) = tg x (sin2x-cos2x)/(sin x * cos x) = tg x - ctg x

(tg x + 1)/(ctg x + 1) = (tg x + 1)/(1/tg x + 1) = tgx(tgx+1)/(tgx+1)=tgx ------------------------------------------------------- (sin2x-cos2x)/(sin x * cos x) = (sin2x-cos2x)/(1/2·sin2x) =2(1-ctg2x)= 2(tg²x-1)/(2tgx)=tgx-1/tgx=tgx-ctgx cbdu