Question

sin^2(20) + cos^4(20) by sin^4(20) + cos ^2(20)
find the value of above. ​

Answer 1

Answer:

cos^4 (20) = cos^2(20)× cos^2(20) = cos^2(20) [ 1- sin^2 (20)]

=> similarly, sin^4 (20) = sin^2 (20) × sin^2(20)

sin^4 (20) => sin^2(20) [ 1 - cos^2(20)]

Now, coming to the given equation,

=> sin^2(20) + cos^4(20) / sin^4(20) + cos ^2(20)

=> {sin^2(20) + cos^2(20) [ 1- sin^2 (20)] } ÷ { sin^2(20) [ 1 - cos^2(20)] + cos^2 (20) }

After this refer to the attached image.