Question

cos⁴A+sin⁴A+2sin²A.cos²A=1​

Answer 1

Step-by-step explanation:

CosA= c

SinA= s

$c ^{4} + s ^{4} = ({c}^{2} + {s}^{2}) ^{2} - 2 {c}^{2} {s}^{2}$

now c^4 + s^4 = 1 - 2c^2s^2

now by rearranging the terms..HP