2x-3x-y+2y+2+x=y+2
Думаю что так
Cosx = 1 - sin^2x
sinx = -2√(2/3)
3cosx = 3 - 3*(-2√(2/3) = 3 - 6√(2/3)
2) sinx = 270
cosx = 1 - (sin^2)[270] = 1 - (√3/2)^2 = 1 - 3/2 = - 1/2
2х^2+6х+9
................
36c - 3(1 + 6c)² = 36c - 3(1 + 12c + 36c²) = 36c - 3 - 36c - 108c² = - 108c² - 3