1. ## Elimination Techniques

Hey Guys, I am having troubles with the last 2 questions:

1. Eliminate t to give an equation that relates x and y:

$\displaystyle x=e^{2t}$ and $\displaystyle y=e^{7t}+5$

The main problem is, I don't quite understand what they are asking for. I THINK, you would solve for t and then plug in t for y?

Such as:
$\displaystyle ln(x)=2t$

So, I would plug this into Y to get:

$\displaystyle y=e^\frac{7}{2}ln(x)$

** That lnx should be in the exponent as well**

2.
Eliminate t to give an equation that relates x and y:
$\displaystyle x=tan(t), y=sec^2(t)-4$

Again, I applied the same principles as above and got this:

$\displaystyle sec^2*atan(x)-4$

Both answers are wrong but I don't see how else you can interpret these questions.

Confused.

2. Originally Posted by mvho
1. Eliminate t to give an equation that relates x and y:

hopefully these equations you attempted to post are correct ...

$\displaystyle x=e^{2t}$

$\displaystyle y=e^{7t}+5$

2.
Eliminate t to give an equation that relates x and y:

$\displaystyle x=\tan(t)$

$\displaystyle y=\sec^2(t)-4$
1. $\displaystyle y = (e^{2t})^\frac{7}{2} + 5$

$\displaystyle y = x^\frac{7}{2} + 5$

2. $\displaystyle y = (1 + \tan^2{t}) - 4$

$\displaystyle y = (1 + x^2) - 4$

3. Thanks skeeter. I can see how you solved the equation now.

I find the wording a little bit tricky.