Question

Complete the first four steps for graphing the quadratic function y = -x^2 - 4x - 3

Answer 1

@jim_thompson5910

Answer 2

are you familiar with completing the square?

Answer 3

No

Answer 4

ok I'll show you how to find the vertex

Answer 5

y = -x^2 - 4x - 3 is in the form y = ax^2 + bx + c

where

a = -1
b = -4
c = -3

Answer 6

we take a = -1, b = -4 and plug them into x = -b/(2a) to get

x = -b/(2a)

x = -(-4)/(2(-1))

x = 4/(-2)

x = -2

Answer 7

So the axis of symmetry is x = -2

That means the x coordinate of the vertex is -2

Answer 8

Plug x = -2 back into the original equation to find the y coordinate of the vertex

Answer 9

y = -x^2 - 4x - 3

y = -(-2)^2 - 4(-2) - 3 .. replace every x with -2

y = -4 - 4(-2) - 3

y = -4 + 8 - 3

y = 1

Answer 10

The x coordinate of the vertex is x = -2, the y coordinate is y = 1

With me so far?