Question

Convert this y=x^2-2x-3 into vertex form, and intercept form

Answer 1

Complete the square of x^2-2x-3

Answer 2

i got (x-3) (x+1)

Answer 3

Not factor. Complete the square.
x^2 - 2x - 3 = (x - 1)^2 - 1 - 3 = (x - 1)^2 - 4
y = (x - 1)^2 - 4 is the vertex form.

Answer 4

But for the intercept form, what you did is correct.
y = (x - 3)(x + 1) is the intercept form.

Answer 5

so the intercept form is always factored ?

Answer 6

Yes, for a quadratic equation, the intercept form is the factored form.

y = (x - 3)(x + 1) is called the intercept form because looking at the factors you can tell the x-intercepts. When x = 3 or -1, y becomes 0. And that is the definition of x-intercepts: What value of x will make y zero? When plotted those are the x values where the graph will cross the x-axis.

Answer 7

what about standard form?

Answer 8

is it just making it into an ax^2+bx+c?

Answer 9

Yes. The equation given in the problem is already in the standard form: y = x^2 - 2x - 3.

Answer 10

how do you convert a vertex into an intercept form?

Answer 11

If you expand the vertex form and simplify, you will get the standard form.
If you factor the standard form you will get the intercept form.

Answer 12

thank you

Answer 13

You are welcome.