Question

cos⁴A + sin⁴A - 2sin²Acos²A = (2cos²A - 1)​

Answer 1

Here is the answer....

Hope this will help you

Answer 2

Step-by-step explanation:

(cos²A-sin²A)²

cos²A-(1-cos²A)

cos²-1+cos²A

2cos²A-1