# Math Help - finding derivative

1. ## finding derivative

If y=tanx how is dx/dt= 2? I dont understand where the 2 came from.

2. ## Re: finding derivative

I think i see now. If something changes 2 units per time unit?

3. ## Re: finding derivative

Originally Posted by droidus
If y=tanx how is dx/dt= 2? I dont understand where the 2 came from.
I don't either (unless it was a given condition). Is there more to this problem that you've not mentioned?

note ...

$\frac{dy}{dt} = \sec^2{x} \cdot \frac{dx}{dt}$

4. ## Re: finding derivative

You give y as a function of x but ask for the derivative of x with respect to t. There must be some other information, such as giving x as a function of t, that you did not post.