My friend just came to me with this problem:(adsbygoogle = window.adsbygoogle || []).push({});

e^x + e^-x = 4

I aced precalc, and I still have no idea where to start on this one. I've factored, natural logged, factored and then natural logged... and I keep running into dead ends.

My graphing calculator puts the answer at +/-1.3169 or something like that.

It's not at all urgent, I'm just curious since I feel that I should know how to solve this problem.

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# Homework Help: Exponential variables

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