Math Is Fun Forum

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Finding the y-coordinate of the vertex of a parabola

Hi;

To find P you solve the system of equations:

So x = 0 and x = -3

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

Deon588

Member

Registered: 2011-05-02

Posts: 68

Re: Finding the y-coordinate of the vertex of a parabola

Thanks a lot bobbym.  Didn't see your post at first as it was on page 2.  g(x):y=-1/2x so then x=-5 which makes more sense as p<q and q=(-4,0).  I totally forgot what to do if I have e.g x^2 +5x.  So x(x+5)
x=0  or  x=-5

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Finding the y-coordinate of the vertex of a parabola

Hi;

Be careful of those signs: g(x):y=-1/2x.

It is g(x) = x / 2.

x = - 3 and x = 0 not x = - 5. Remember the final equation is x(x+3) = 0.

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.