Thread: Parametric Equations- Take 2

1. Parametric Equations- Take 2

The graph of the parametric equations

meets the graph of the parametric equations

at two points. Find the slope of the line between these two points.

So far, I tried equating x's and y's, but got

cos(t) = 2+ 4cos(s)
sin(t)= 3+ 4sin(s)

How can I add those and continue from there? Thank you!

2. Re: Parametric Equations- Take 2

You are trying to find relationships between s and t. That is very difficult. Instead, try to find relationships between x and y. What do you get from $x^2+y^2$ (use the first parametric equation)? What about (x-2)^2+(y-3)^2 (use the second parametric equation)?

3. Re: Parametric Equations- Take 2

Thanks, Slip! Using the cos^2+sin^2=1 theorem I ended up with

4 cos(s) = -7 -6 sin (s)

So x= 2 + -7 - 6 sin(s)

And adding that to the other equation, y=3+4sin(s), I ended up with

6y + 4x = -2
And from this I can get y= -2/3 x -1/3

So is the slope -2/3? I took an intuitive approach and aren't 100% sure if I did it right

4. Re: Parametric Equations- Take 2

That is correct

5. Re: Parametric Equations- Take 2

Thanks again!