If f(x)= (4cos^4x+2cos^2x+2sin^2x-x^9-1/2cos4x)^(1/9). Find f(f(2))

Answer 1

just plug and chug!
f(2) = -509.8^(1/9) = -1.999 ≈ -2
f(-2) = 514.1927^(1/9) = 2.0009 ≈ 2