I need calculus help.

Find the differential of the function y=2tan(x)
i found that to be 2sec^2(x) which is correct.
next i need to Evaluate dy and Δy when x=π/4 and dx=−0.2

what is dy: and Δy:

Question

I need calculus help.

Find the differential of the function y=2tan(x)
i found that to be 2sec^2(x) which is correct.
next i need to Evaluate dy and Δy when x=π/4 and dx=−0.2 

what is dy: and Δy:

zepdrix · Answer

Ok now the problem makes more sense :) lol
$$\large dy=2(\sec^2x) dx$$
When x=pi/4, dx=-0.2, just plug the values in! :D$$\large dy=2\left(\sec\frac{\pi}{4}\right)^2 (-0.2)$$Having any trouble evaluating this?

anonymous · Answer

no i see that now. so are dy and delta y the same?

zepdrix · Answer

Hmm I'm not quite sure what's going on with that delta y :(

anonymous · Answer

yeah i have no clue. I got understand the dy though so thanks a lot for the help with that one. Sorry about the type on the last problem. haha

zepdrix · Answer

XD