Question

find vertex of : f(x)=2x^2+8x+12

Answer 1

Shall we "Complete the Square" or just the formula, -b/2a?

Answer 2

complete the square

Answer 3

This is how I do it. I start by making it look like it needs to look when I'm done.

f(x) = 2(x^2 + 4x + ______) + 12 - 2(______)

The two blanks are the same. With what number shall we fill them?

Answer 4

2? don't we take half of the middle term?

Answer 5

2? No. Half the middle coefficient and then square it.

4/2 = 2
2^2 = 4

Put 4 in the two blanks and simplify.