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    Edexcel P5 Hyperbolics... can't remember anything to do with bloody exponentials.
    Need to solve coshx=5/3 finding x and e^x.

    I have also found sinhx=+/- 4/3 as the question asks for it using osbournes rule and converting sin^2+cos^2=1.
    It uses the word hence so I think this is probably a clue to usethe sinh variation.
    Know sinhx is as checked ansers in book

    Just need an example I can follow for the rest of the homework.

    Regards,
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    coshx = 5/3

    \Rightarrow e^x + e^{-x} = \frac{10}{3}

    \Rightarrow e^{2x}+1  = \frac{10}{3} e^x

    \Rightarrow e^{2x} - \frac{10}{3} e^x + 1 = 0

    solve this as a quadratic in e^x.
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    Cheers I never thought of doing like that... I must remember the power of quadratics.
    Thanks once again
 
 
 
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