Question

ow to find the range of a quadratic function f(x)=x^2-8X+3

Answer 1

do you know how to turn this into the form of the last question?

Answer 2

NO IM O SURE OW TO?

Answer 3

or you can use the fact that \(f(\frac{-b}{2a})\) will give you the y point of the vertex

Answer 4

do you understand me?

Answer 5

hmmmm u mean find the coordinates of the vertex first

Answer 6

first find \(x=\frac{-b}{2a}\), then plug that into the equation. you will get out the y value of the vertex, then use that and the fact that the graph is facing up or down, to do the range

Answer 7

4,-13

Answer 8

correct, and what way is the graph facing?

Answer 9

I am not sure do I look at x^2-8x+3 to find out??? I would assume with a +3 it faces up

Answer 10

the fact that the coefficient on the first term is positive (its 1) tells us that it is facing up

Answer 11

the +3 tell us where it crosses the y-axis but tells us nothing about if it is facing up or down

Answer 12

ok to be sure you mean if its a negative x^2 IT WOULD FACE DOWN BUT SINCE ITS POSITIVE IT GOES UP

Answer 13

correct

Answer 14

[-13,inf)

Answer 15

2x^2+3x-4 and 3x^2-15x+17 both face up

Answer 16

correct

Answer 17

nice work

Answer 18

thanks