Question

prove that sin square theta + cos square theta = 1

Answer 1

Hope this will help you

Answer 2

Consider a right-angled triangle, ΔABC, where ∠BAC=θ,



By the Pythagorean theorem,AC2+BC2=AB2Dividing by AB2,⇒AC2AB2+BC2AB2=AB2AB2⇒(oppositehypotenuse)2+(adjacenthypotenuse)2=AB2AB2=1⇒sin2θ+cos2θ=1