7/x - 2e^x

Find an anti-derivative of f(x)

I almost have it correct I think but I'm messing something up. I moved x to the top making it 7x^-1 - 2e^x but I am unsure how take the derivative of -2e^x

Question

7/x - 2e^x

Find an anti-derivative of f(x)

I almost have it correct I think but I'm messing something up. I moved x to the top making it 7x^-1 - 2e^x but I am unsure how take the derivative of -2e^x

anonymous · Answer

wolframalpha my friend

anonymous · Answer

http://www.wolframalpha.com/

savvy · Answer

$$7\ln x - 2e ^{x} + c$$

anonymous · Answer

thank you! how did you know to to change 7 into a natural log?

savvy · Answer

dont write 1/x as x^-1..... instead remember the anti derivative of 1/x is $$\ln x$$..
and the anti derivative of $$e ^{x}$$ is $$e ^{x}$$ itself...

savvy · Answer

i didn't change 7 into natural log....it was 1/x which got transformed to lnx through integration...

zarkon · Answer

I would write the antiderivative of $\displaystyle \frac{1}{x}$ as $\displaystyle\ln|x|+c$