Question

2(1-cos^2x)+cos^2x=1+sen^2x

Answer 1

2(1-cos^2x)+cos^2x=1+sen^2x 
2(sen^2x) + cos^2x = 1+sen^2x 
2(sen^2x) = 1+sen^2x - cos^2x 
2sen^2x = 1-cos^2x + sen^2x 
2sen^2x = (1-cos^2x) + sen^2x 
2sen^2 = sen^2x + sen^2x 
2sen^2 = 2sen^2