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**CIV****Member**- Registered: 2014-11-09
- Posts: 69

I'm doing some Calculus 1 homework and I've come to a problem that I just cant figure out. I need to find where the slope of the equation below is zero.

I got the derivative without any trouble: 2x + 4cosx.

I can't figure out how to find the solution(s) though. I know that cosx = 0 at PI/2, but that isn't helping me here. I know I can factor out 2 as well, so: 2(x+2cosx) = 0.

What do I do?

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**alter ego****Member**- Registered: 2012-03-30
- Posts: 19

Hi CIV,

There isn't an exact value for this so you'll have to give an approximate value. On the MathsIsFun main site there is a function plotter. You can plot -x as one line and 2cosx as a curve. Zoom in to get your answer where they cross.

Alter

*Last edited by alter ego (2017-11-01 00:49:30)*

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