Question

sin^4 +cos^4 =1-2sin^2 cos^2 

Answer 1

[cos²@ + sin²@]² = cos⁴@ + sin⁴@ + 2.sin²@.cos²@

so, sin⁴@ + cos⁴@ = 1 - 2.sin²@.cos²@

Answer 2

Hi I hope my answer in last 2 questions helps you bye