SOLUTION: this problem isn't from a book. It simply says "solve" a^4-5a^2+4=0 Can you help me with this? Thank you, Anne

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Question 142906: this problem isn't from a book. It simply says "solve"
a^4-5a^2+4=0 Can you help me with this? Thank you, Anne
Answer by vleith(2983) About Me  (Show Source):
You can put this solution on YOUR website!
Anne, I bet you can solve this equation
b%5E2+-+5b+%2B+4=0
You would factor and get
%28b+-+4%29%28b+-1%29+=+0+ and then solve for b

So how is the given problem different than the one above? If you set b+=+a%5E2, they are the same.
Thus
a%5E4-5a%5E2%2B4=0+
%28a%5E2+-4%29%28a%5E2+-1%29+=+0+
Solving yields a^2 = 4 and a^2 = 1
Take the square roots and you'll get 4 solutions.
Make sense?