# Check my precalc?

posted by
**Rebekah** on
.

#1: f(x) = x^2-4x

find vrtex, axis ofsym, y-int, x-int if any, domain, range, where increasing and decreasing.

I got.... vertex: 2,4

axis of sym: x=2

D= (-infinity, infnity)

range= [4,infinity)

im stuck of the intercepts because when i plug i 0 for x i get yint of 0 but the graph doesnt show that.

Am i doing the completingthe square wrong

I got (x^2-2)^2 + 4

#2 Same requirements as the first question

f(x)= x^2 + 6x +9

I got... vertex: (-3,18)

axis of sym: x=-3

Domain= (-infinity, infinity)

Range= [18, infinity)

y-int (0,9)

x-int idk???

After completing the square I got:

(x+3)^2 + 18

Also a question, how do you know if there is an x or y int without drawing the graph because my graph des not show a xint but the equation does?

Thanks!