Question

how many local maxima and minima does the polynomial y=-5x^2 +6x+9 have?
maxima______ minima______

Answer 1

no min
max at
\[x=\frac{-b}{2a}\]

Answer 2

answer to "how many" is one and none respectively

Answer 3

differentiate function. dy/dx=-10x + 6. differentiate one more time to know whether it's max/min. You get d^2y/dx^2 = -10, which is negative, so it's a maximum

Answer 4

by the way all functions of the form ax^2+bx+c always have only 1 maxima/minima; if a is negative it's a maxima, if a is positive it's a minima.

Answer 5

how did u find that sattelite

Answer 6

If u diff ax^2 +bx + c -> 2ax +b = 0 for min/max ie x= -b/2a

That is where the formula comes from.