# Homework Help: Equation of y vs x

1. Nov 2, 2004

### UrbanXrisis

if:
x=4.28t+0.181
y=6.47t^2+4.51t+0.455

what is equation of the graph of y vs x?

I lost all my data for this physics project and all I have left are these notations. I would be able to find an equation if I had my graph. Any help would be appreciated.

-UX

2. Nov 2, 2004

### Pyrrhus

those are parametric equations isolate t, then substitute in the other, and graph it.

3. Nov 2, 2004

### UrbanXrisis

I didn't catch that, can you explain it in more detail?

4. Nov 2, 2004

### Leong

I think he means that find t in term of x and subsitute the t into the second equation of yours.

5. Nov 2, 2004

### Pyrrhus

sorry, i was away, yes what leong said.

6. Nov 2, 2004

### UrbanXrisis

ahh...so it's similar to a system of equations

7. Nov 3, 2004

### CeeAnne

Urban, the graph of the equations would be a parabola. I'm not real good at math but I think you can graph the equation by substituting values for t in both equations and evaluating to get the x and y points for each value of t. For instance, for t=0, x=0.181 and y=0.455 ... for t=1, x=4.461 and y=11.435 ... for t=2, x=8.741 and y=35.355 and so on for as many + and - values of t as you need. Plot the points and connect them as a smooth curve.

8. Nov 3, 2004

### HallsofIvy

Yes, but that's irrelevant to the question asked.

9. Nov 6, 2004

### CeeAnne

Well, Ivy, I don't believe it is irrelevant. Urban did say the equation could be found with the graph and any help would be appreciated.