Mathematics Stack Exchange is a question and answer site for people studying math at any level and professionals in related fields. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

Doing my final review for the semester and just want to make sure I have all my bases covered. (I'll more than likely have another 4-5 question to come today, but I'll start here).

Looking for someone to confirm whether this is the correct answer or not. If not, can you explain where I've gone wrong.

Find the equation of the tangent line to $y = 2xe^{-x}$ at the point (0,0)

1 (find derivative) :

$$ y' = 2(e^{-x}) + 2x(-e^{-x}) $$

2 (plug in x) :

$$ 2(e^{-0}) + 2(0)*(-e^{-0}) = 2(1) + 2(0)*(-1) $$

3 (plug that in to point slope formula) :

$$ y - 0 = 2(x + 0) --> y = 2x $$

Is this the correct answer?

share|cite|improve this question
Yes, indeed it is. – David Mitra Dec 12 '12 at 16:57
@DavidMitra Thank you for the confirmation. Feels nice to know I'm on the right track for the final! Hope you stick around as I'll have some more questions shortly. – StrugglingWithMath Dec 12 '12 at 16:58

Looks good to me. (30 characters? Bah.)

share|cite|improve this answer
There should be a link icon above the editing window that will aid you. – David Mitra Dec 12 '12 at 17:02
Thanks, that helped. – user108903 Dec 12 '12 at 17:08

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.