# Homework Help: Parametric equation help

1. Mar 7, 2006

### lakitu

hi apologise if this is in the wrong forum :)

my lecturer has told me that i need to be able to express parametric equations as a cartesian equation in my exam later this month. my mind boggles !

here is an example i have found.

Express the parametric equations x = 2 t - 2 and y = 3 t - 2 as a Cartesian equation in just x and y.

any help would be great!

kind regards lakitu :)

2. Mar 7, 2006

### Integral

Staff Emeritus
Solve your x and y equations for t. Then since both are equal to to t you can eliminate the t.

3. Mar 8, 2006

### lakitu

hi thank you i will give that a go :)

lakitu

4. Mar 8, 2006

### lakitu

x = 2 t - 2 -----------------(1)
y = 3 t - 2 -----------------(2)

multiply (1) by 3 and (2) by 2.

3x = 6 t - 6 -----------------(3)
2y = 6 t - 4 -----------------(4)

we can now eliminate t from the two eqns by subtracting (4) from (3)

3x - 2y = -6 + 4
3x - 2y = -2

how does this look to you ?

5. Mar 8, 2006

### Hootenanny

Staff Emeritus
Looks good to me.