Udowodnij 2 tożsamości trygonometryczne 1 cosx/(1+tg x) + sinx/(1+ctg x) = 1/sinx+cosx 2. tg ^2x - sin^2x = tg^2x × sin ^2x

tg ^2x - sin^2x = tg^2x × sin ^2x L = tg^2x - sin^2x = = sin^2x/cos^2x - sin^2x = = sin^2x - sin^2xcos^2x/cos^2x = = sin^2x(1-cos^2x)/cos^2x = = sin^2x * sin^2x / cos^2x = = sin^4x/cos^2x = = sin^2x/cos^2x * sin^2x = = tg^2xsin^2x = P L = P :)