y=x2+6x−12y = x^{2} + 6x - 12y=x2+6x−12
dydx=2x+6=0\frac{dy}{dx} = 2x + 6 = 0dxdy=2x+6=0
2x=−6 ⟹ x=−32x = -6 \implies x = -32x=−6⟹x=−3
y(−3)=(−3)2+6(−3)−12=9−18−12=−21y(-3) = (-3)^{2} + 6(-3) - 12 = 9 - 18 - 12 = -21y(−3)=(−3)2+6(−3)−12=9−18−12=−21
