Pls explain this! 5. 7.EE.1.2 Which of the following is not a solution for
finding the perimeter of the square?
29+2
A. 4(2y + 2)
B. 8y + 8
C. (2y + 2) + (2y + 2) + (2y + 2) + (2y
+ 2)
D. 4y + 4

Prove (a) cosh2(x) − sinh2(x) = 1 and (b) 1 − tanh 2(x) = sech 2(x). solution (a) cosh2(x) − sinh2(x) = ex + e−x 2 2 − 2 = e2x + 2 + e−2x 4 − = 4 = . (b) we start with the identity proved in part (a): cosh2(x) − sinh2(x) = 1. if we divide both sides by cosh2(x), we get 1 − sinh2(x) cosh2(x) = 1 or 1 − tanh 2(x) = .

Ijust need these 2 questions answered (the second pic is just confirmation i'm not confident in that answer)

Cos^2x+cos^2(120°+x)+cos^2(120°-x)i need this asap. pls me