(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Prove

cosh(2x)= cosh^2(x) + sinh^2(x)

2. Relevant equations

sinh(x) ≡ [ e^(x) - e^(-x) ] / 2

cosh(x) ≡ [ e^(x) + e^(-x) ] / 2

3. The attempt at a solution

= { [ e^(x) + e^(-x) ] / 2 }² + { [ e^(x) - e^(-x) ] / 2 }²

= [ e^(x) + e^(-x) ]² / 2² + [ e^(x) - e^(-x) ]² / 2²

.... gets confusing after this. Thanks in advance.

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# Homework Help: Calc- prove sinh(x) and cosh(x) identities?

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