Proszę o pomoc! Przedstaw w prostszej postaci: a) (cosα tgα)² - (sinα ctgα) b) sinα cosα (tgα + ctgα) c) sinα(sinα + ctgα cosα)   Pomocyyy!!!!

a) [latex](cosalpha*tgalpha)^2 - (sinalpha*ctgalpha) = left(cosalpha*frac{sinalpha}{cosalpha} ight)^2 - sinalpha*frac{cosalpha}{sinalpha} = sin^2alpha - cosalpha[/latex]   b) [latex]sinalpha * cosalpha(tgalpha + ctgalpha) = sinalpha * cosalphaleft(frac{sinalpha}{cosalpha} + frac{cosalpha}{sinalpha} ight) = sinalpha * cosalpha * frac{sin^2alpha + cos^2alpha}{cosalpha * sinalpha} = sin^2alpha + cos^2alpha = 1[/latex]   c) [latex]sinalpha(sinalpha+ctgalpha*cosalpha) = sin^2alpha+ctgalpha*cosalpha*sinalpha = sin^2alpha+frac{cosalpha}{sinalpha}*cosalpha*sinalpha = sin^2alpha+cos^2alpha = 1[/latex]