We know that: sinh(2x) = 2sinh(x)cosh(x) , therefore the equation becomes 6sinh(x)cosh(x) = 13 - 3e2xWe also know that sinh(x) = 0.5*[ex-e-x] and that cosh(x) = 0.5*[ex+e-x], so the equation can be expanded into :
6/4[e2x-e-2x] = 13 - 3e2x3e2x -3e-2x = 26 - 6e2x
Rearrange and multiply by e2x to get a quadratic in e2x:9e4x - 26e2x - 3 = 0
Use Quadratic formula to find possible values for e2x.Since e2x must be greater than zero, only one answer is valid.Simply rearrange that answer to find the value of x.Answer: x = 0.5ln3
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