110k views
4 votes
F(x) = 4(x + 2)2 - 1 What is the vertex?

User PjoterS
by
8.7k points

1 Answer

4 votes

You have the following function:

f(x) = 4(x + 2)² - 1

In order to find the vertex of the previous function, expand the factor (x + 2)²:

f(x) = 4(x² + 4x + 4) - 1

f(x) = 4x² + 16x + 16 - 1

f(x) = 4x² + 16x + 15

the previous result has the general form:

f(x) = ax² + bx + c

by comparing the previous expression with the result for the given function you have:

a = 4

b = 16

c = 15

the vertex of the function f(x) is given by:

x = -b/2a

by replacing the values of parameters b and a you obtain:

x = -16/2(4)

x = -16/8

x = -2

Next, to find the vertex, it is necessary to calculate f(-2):

f(-2) = 4(-2 + 2)² + 1

f(-2) = 0 + 1

f(-2) = 1

Hence, the vertex is (-2,1)

User Steve Buzonas
by
7.4k points

No related questions found

Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.

9.4m questions

12.2m answers

Categories