Verify the identity. (2 cost 7 sin t)2 + (7 cost + 2 sin t) = 53 To verify the identity, start with the more complicated side and transform it to look like the other side. Choose the correct transformations and transform the expression at each step. (2 cost-7 sint)2 + (7 cost + 2 sint) (Do not factor.) Apply a Pythagorean identity. Factor out the greatest common factor. Square each of the binomial expressions and combine like terms.