SOLUTION: x^4 + 7x^2 – 8 = 0 Please help me with this. Thanks

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Question 224463: x^4 + 7x^2 – 8 = 0 Please help me with this. Thanks
Answer by drj(1380) About Me  (Show Source):
You can put this solution on YOUR website!
x%5E4%2B7x%5E2-8=0

x%5E4%2B7x%5E2-8=%28x%5E2%2B8%29%2A%28x%5E2-1%29=0

x%5E2%2B8=0 and x%5E2-1=0

x%5E2=-8 and x%5E2=1

Take the square root to both sides of the equation

x1=i%2A2sqrt%282%29 where i=sqrt%28-1%29
x2=-i%2A2sqrt%282%29
x3=1
x4=-1

ANSWER: The solutions are: x1=i%2A2sqrt%282%29, x2=-i%2A2sqrt%282%29, x3=1 and x4=-1

I hope the above steps were helpful.

For FREE Step-By-Step videos in Introduction to Algebra, please visit http://www.FreedomUniversity.TV/courses/IntroAlgebra and for Trigonometry visit http://www.FreedomUniversity.TV/courses/Trigonometry.

Good luck in your studies!

Respectfully,
Dr J