## mitchelsewbaran 2 years ago Write the quadratic function in vertex form. y = x^2 + 8x + 18

1. ParthKohli

Do you know how to complete the square?

2. mitchelsewbaran

(b/2)^2

3. ParthKohli

Yes, so can you apply that here? I'm sure you can...

4. mitchelsewbaran

here are the choices: y = (x - 4)^2 - 2 y = (x - 4)^2 + 2 y = (x + 4)^2 - 2 y = (x + 4)^2 + 2

5. ParthKohli

Okay, but can you add $$\left(b\over 2\right)^2$$ to both sides? Do you know what $$b$$ is?

6. mitchelsewbaran

8

7. ParthKohli

So what would $$\left(b\over 2\right)^2$$ be?

8. mitchelsewbaran

16?

9. ParthKohli

Yes, so add $$16$$ to both sides. :-)

10. mitchelsewbaran

y = (x + 4)^2 - 2

11. ParthKohli