Originally Posted by

**Siron** If you've a polynomial in the form:

$\displaystyle y=a(x-h)^2+k$

then like you said, you can determine the coordinates of the vertex directly: (h,k)

If you've a polynomial in the form:

$\displaystyle y=ax^2+bx+c$

then you've to convert this polynomial into the form $\displaystyle y=a(x-h)^2+k$

In case of your exercice, you have given a polynomial in the form $\displaystyle y=ax^2+bx+c$ so convert it to the other form (by using 'completing the square, like you did in your previous topic)

So, can you write:

$\displaystyle y=x^2-10x-8$ into the form: $\displaystyle y=a(x-h)^2+k$?