Question

Which of the following is the vertex of the function? y = x2 - 14x + 13
A. (1, 0)
B. (3, -20)
C. (5, -32)
D. (7, -36)

Answer 1

You need to complete the square

Answer 2

Do you know how to do that?

Answer 3

kinda

Answer 4

\[y=(x^2-14x)+14\]
Then I take half the x coefficient and square it. Then I add and subtract that number
\[y=(x^2-14x+49-49)+14\]
Then I bring the minus number out of the brackets
\[y=(x^2-14x+49)-49+14\]
Now, what we have done is forced the brackets to be a perfect square. So we can factor
\[y=(x-7)^2-49+14\]
And just simplify
\[y=(x-7)^2-35\]
Now that it is in vertex form, we can see that the vertex is (7,-35)

Answer 5

Ok?

Answer 6

wow yes!

Answer 7

Just remember...that in the step where we bring the negative 49 out of the brackets, if there is a number in front of the brackets, you would have had to multiply the -49 by that number when you bring it out.

Answer 8

okay!:)