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L asked in Science & MathematicsMathematics · 8 years ago

Exponent problems with i and Euler's formula?

e^(2πi) = 1, so (e^(πi))² = 1. When x²=1, x=±1. Shouldn't e^(πi)=±1? What prevents e^(πi) from equaling 1?

Also,

e^(2πi) = 1, so one of the 2πi roots of 1 must be e. But e is not on the unit circle in a complex plane. How is this possible?

1 Answer

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  • Anonymous
    8 years ago
    Favorite Answer

    For your first question, it is true that e^{πi} = -1. The thing to remember is that for a complex number z = x+iy, we have e^z = e^x(cos(y) + i*sin(y)). So e^{πi} = (e^0)(cos(π) + i*sin(π)) = 1*(-1 + i*0) = -1.

    For the second question, you're again right that e is one of the 2πi-th roots of 1, but it's not true that a complex root of 1 should have modulus 1, as you've just observed.

    Source(s): Mathematics student.
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