What’s the exact value of cos(127.5)? using trig identities like half angle and explain

For the function, f(x) = -5x 2, find f(-4).

F(x)= 4x g(x) =x-1 what is f(x) divided by g(x)

Solve: 25 points find the fifth term of an increasing geometric progression if the first term is equal to 7−3 √5 and each term (starting with the second) is equal to the difference of the term following it and the term preceding it.