## anonymous one year ago How could I go about solving this problem: If x^2+y^2=25 and dy/dt=6, find dx/dt when y=4 and x=3.

1. Astrophysics

$2x \frac{ dx }{ dt } + 2y \frac{ dy }{ dt } = 0$ differentiate both sides wrt to t. Now find dx/dt and plug in the values.

2. anonymous

Ohhh okay! Thanks so much! :)

3. Astrophysics

It's implicit differentiation :)

4. Astrophysics

No problem!

5. anonymous

Right! I always get confused about the "with respect to..." part xD but I got what you did here! :D

6. Astrophysics

You may have got confused because you may not be used to differentiating with respect to t, which just means x and y are functions of t :)

7. anonymous

Ahhh that's true! That makes total sense haha XD

8. anonymous

Many thanks! :D

9. Astrophysics

Np :)