Posted by **suie** on Tuesday, February 5, 2013 at 8:48pm.

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

- pre-calculus -
**Damon**, Tuesday, February 5, 2013 at 9:01pm
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 -
**suie**, Tuesday, February 5, 2013 at 9:03pm
but the answers are 0,-2,2

- pre-calculus -
**Reiny**, Tuesday, February 5, 2013 at 9:36pm
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 -
**suie**, Tuesday, February 5, 2013 at 9:52pm
are u sure b/c the answers are from the book

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