Question

Find either the maximum or the minimum value of the following quadratic equation. Be sure to show all of your work and identify the maximum or minimum value correctly.

y = 5x^2 - 10x - 4

Answer 1

the minimum is (1,-9)

Explanation:

y = 5x^2 - 10x - 4

since the parabola opens upward 5>0, this will have a minimum

it will occur along the axis of symmetry h=-b/2a

y =ax^2 +bx+c

h = -(-10)/2*5

h = 10/10 =1

the minimum occurs at x =1

the y value for the minimum is calculated by substituting x =1 back into the equation

y = 5 * 1^2 - 10*1 -4

y = 5*1^2 -10 -4

y = 5-10-4

y = -9

the minimum is (1,-9)