найти cosα, tgα, ctgα если sinα=5/13 и π/2<α<π

sinα=5/13, α∈(π/2, π)cosα=-√(1-sin²α)=-√(1-25/169)=-√(144/169)=-12/13tgα=sinα/cosα=(5/13)/(-12/13)=-5/12ctgα=1/tgα=1/(-5/12)=-12/5