Question

What is the range of the quadratic function
f(x) = -5x2 + 30x + 2?

Answer 1

Find the vertex. Since this parabola is concave downward, the range will be all y values less than or equal to the y coordinate of the vertex.

Answer 2

(-oo,2]

Answer 3

The vertex is (3,47)

Answer 4

Vertex ( h, k)
h = - b/ 2a = 30/10 = 3

Answer 5

f ( 3) = 47
=> Range ( -∞, 47)

Answer 6

So the range is all real numbers less than or equal to 47

Answer 7

(-3.5,47.08)