5.2 Properties of Parabolas. y = ax2 + bx + c y = -ax2 + bx + c which way do they open? which one has max and which one min? Important points of a parabola. y = x2 + 3x - 4 X 0 Y Important points of a parabola. y= x2 + 3x - 4 x = - b/2a gives you half of vertex. to find the other half, plug it in. x = -3/ (2*1) = -1.5 the max/min value HAPPENS here. y = x2 + 3x - 4 the VALUE of the max/min is what you get when you plug in -1.5 y = (-1.5)2 + 3(-1.5) - 4 = -6.25 V = (-1.5, -6.25) reflect to get other points! Your small business determines that profits are maximized with equation: y = -2x2 + 15x + 5 x = workers employed y = profits (in thousands) what number of workers make the company most profitable? what is the profit? Problems to do: pg. 248 23, 25, 28-30, 35-39, 41-43.