the max or min of a quadratic is at the vertex of the parabola. I expect you can determine whether the vertex is a max or a min.
So, since the vertex is at x = -b/2a,
(2) -3x^2-6x-9
the vertex is at x = -6/(2*-3) = 1
y(1) = -18, so the vertex is at (1,-18)
(3) the vertex of y-k = a(x-h)^2 is at (h,k), so
the vertex is at (4,7)
(4) -x^2-2x+3
= -(x^2+2x+1)+3+1
= -(x+1)^2 + 4
(5) note that 42 = 6*7
(6) the discriminant is 5, so
x = (-13±5)/12 = -3/2, -2/3
(3x+2)(2x+3)
(7) 4x^3 - 81x
= x(4x^2 - 81)
= x(2x+9)(2x-9)
1.) The cost in C dollars of manufacturing x bicycles at Holliday's Production Plant is given by the function C(x) = 2x2 - 800x + 92,000. Find the minimum cost.
2.) The vertex of y = -3x2- 6x - 9 lies in which quadrant?
3.) Given f(x) = 1/3*(x - 4 )2 + 7.
Identify the vertex.
4.) Write f(x) = -x2 - 2x + 3 in vertex form.
5.) Factor x2-13x + 42.
6.) Factor 6x2+13x + 6.
7.) Factor completely 4x3 - 81x.
1 answer
1 answer