pre-calculus

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x^3e^x - 4e^x =0

  • pre-calculus -

    e^x (x^3 - 4) = 0

    e^x = 0
    x = -oo

    x^3 = 4

    x = 4^(.333....)

    Not sure if you do complex arithmetic

    360/3 = 120
    if so you also have two complex roots
    one at +120 degrees and one at - 120
    x = r (cos 120 + i sin 120)
    x = 4^(1/3) ( -.5 + i sqrt3/2)
    x = 4^.3333...(.5)(-1+isqrt 3)

    and the other is
    x = 4^.3333...(.5)(-1-isqrt 3)

  • pre-calculus -

    but the answers are 0,-2,2

  • pre-calculus -

    If the equation is as you typed my money is riding with Damon.

    Your answers don't even come close to satisfying the equation.

  • pre-calculus -

    are u sure b/c the answers are from the book

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