Question

if cosA+cos²A=1 then find the value of sin²A+sin^4A

Answer 1

cos A + cos^2 A = 1 --------(1)

=> cos A = 1 - cos^2 A

=> cos A = sin^2 A ---------(2)


Now,

sin^2 A + sin^4 A

= cos A + Cos^2 A (using equation 2)

= 1 (using equation 2)