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Mathematics 10 Online
OpenStudy (anonymous):

e^x + e^-x = 2

OpenStudy (anonymous):

x = 0

OpenStudy (anonymous):

\[e^x + \frac{1}{e^x} = 2\]

OpenStudy (anonymous):

Solve this you will get quadratic equation..

OpenStudy (anonymous):

yes obviously x=0 as 1+1=2 gives a perfect solution :)

OpenStudy (anonymous):

how will i get a quadratic equation?

OpenStudy (callisto):

Multiply both sides by e^x

OpenStudy (anonymous):

Or let y = e^x, solve for y.

OpenStudy (anonymous):

\[e^{2x} + 1 = 2e^{x} \implies e^{2x} - 2e^x + 1 = 0\]

OpenStudy (anonymous):

\[(e^x -1)^2 = 0\]

OpenStudy (anonymous):

\[e^x = 1\]

OpenStudy (callisto):

\[e^x + \frac{1}{e^x} = 2\]\[e^x(e^x + \frac{1}{e^x}) = 2e^x\]\[e^{2x} + 1 = 2e^x\]\[(e^{x})^2 + 1 = 2e^x\]\[(e^{x})^2 -2e^x+ 1 = 0\]

OpenStudy (anonymous):

Clerly x is 0..

OpenStudy (anonymous):

thank you :)

OpenStudy (anonymous):

Anything raised to the power 0 except 0 is 1..

OpenStudy (anonymous):

have a nice day! see you after next chapter :)

OpenStudy (lgbasallote):

interesting...i see a trig function =))

OpenStudy (anonymous):

So for e^x =1 , x must be 0..

OpenStudy (anonymous):

@lgbasallote I too..

OpenStudy (anonymous):

You probably mean a hyperbolic trig function, lg: cosh x = 1.

OpenStudy (anonymous):

trig function where?

OpenStudy (anonymous):

If x is pure imaginary, your equation can be expressed with a cosine, e.g. if x = i y then you have cos(y) = 1. You still get the same answer, of course, y = x = 0.

OpenStudy (anonymous):

Oh com' on @bronzegoddess and @Carl_Pham lgba was just joking and you took him seriously..

OpenStudy (anonymous):

lol my bad

OpenStudy (anonymous):

So?

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