Sin squared-2sincos+cos square+sin squared+2sincos+cos squared.
There is a formula wherein
Sin squared+cos squared=1
Cancel the 2sincos for they are like terms and like terms need to add. Then substitute
Sin squared-cos squared+1=?
By the formula earlier, transposing the cos squared would result to:
Sin squared=1-cos squared
Sin squared+Sin squared=2sinsquared
Hope it helps =)