Question

What is the vertex of the graph of y = –4(x + 2)2 + 5?

(2, 5)

(–2, 5)

(5, –2)

(5, 2)

Solve. 5x2 – 20 = 0

x = 5 and x = 4

x = 4 and x = 2

x = –5 and x = 20

x = 2 and x = –2

I think the first one is A and the second one is C

Answer 1

@phi

Answer 2

@Callisto

Answer 3

the vertex is (-h, k) isn't it? so the vertex should be (-2, 5)

Answer 4

look at this
http://www.mathwarehouse.com/geometry/parabola/standard-and-vertex-form.php

can you figure it out ?

Answer 5

ah no

Answer 6

5x^2 – 20 = 0
5x^2 = 20
x^2 = 4
sqrt(x^2) = +/- sqrt(4)
x = +/- 2

Answer 7

so the second one is d

Answer 8

does that make sense?

Answer 9

yes.

Answer 10

ok :]

Answer 11

what about the first one ?

Answer 12

look at my first post