SOLUTION: Can you please help me solve this? I have to solve for all roots. {{{x^4-5x^2-24=0}}}

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Question 189610: Can you please help me solve this? I have to solve for all roots. x%5E4-5x%5E2-24=0
Answer by nerdybill(7384) About Me  (Show Source):
You can put this solution on YOUR website!
x%5E4-5x%5E2-24=0
Notice that x^4 = (x^2)^2
.
%28x%5E2-8%29%28x%5E2%2B3%29=0
.
Setting each expression in parentheses equal to zero and solve for x:
(x^2-8)=0
x^2 = 8
x = +- sqrt(8)
x = +- 2sqrt(2)
.
(x^2+3)=0
x^2 = -3
x = +- sqrt(-3)
x = +- sqrt(3)i