Question

determine o valor numérico das expressões para x=r
y=cos 4x+sen2x+tg2x-sen 8x

Answer 1

$y=cos 4x+sen2x+tg2x-sen 8x \\ y=cos 4\pi+sen2\pi+tg2\pi-sen 8\pi \\ y=1+0+0-0 \\ y=1$