# Parameter equation

1. Nov 27, 2007

### baokhuyen

1. The problem statement, all variables and given/known data

How can I eliminate tha parameter of these equations:
x=sec x, y=tan x

2. Relevant equations

3. The attempt at a solution

2. Nov 27, 2007

### Dick

Square them and subtract.

3. Nov 28, 2007

### HallsofIvy

Staff Emeritus
You can't if there is NO parameter. I assume you meant x= sec t, y= tan t. As Dick said, square and subtract- you are using a simple trig identity.