1. Jan 10, 2005

### footprints

$$y=4x^2-8x-5$$ Find the coordinates of the turning point of the curve. Where do I even start?

2. Jan 10, 2005

### Hurkyl

Staff Emeritus
With the definition of turning point.

3. Jan 10, 2005

### footprints

I don't know that.

4. Jan 10, 2005

### Hurkyl

Staff Emeritus
Well, then, that's where you need to start. What does your book have to say, or your notes?

(Incidentally, what level math is this?)

5. Jan 10, 2005

### footprints

My book doesn't say anything about the definition of a turning point. I'm in grade 9.

6. Jan 10, 2005

### danne89

If you mean the minimi/maximi-point of the curve, you can set the derivate equal to zero and solve. Wait a minute, it must be an another way... Try to completting the square on the function...

7. Jan 10, 2005

### Hurkyl

Staff Emeritus
Where did you see the problem?

If I had to guess what it meant, I would say the point where the graph of the polynomial stops going downwards and starts going upwards. Since it's a parabola, that would be its vertex.

8. Jan 10, 2005

### footprints

Oh Yes!! Now that you guys mention that, I know what to do now Thanks!!

Last edited: Jan 10, 2005