SOLUTION: can you please help me find the complex and real zeros of the function: {{{4x^4-21x^2-25}}}

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Question 474138: can you please help me find the complex and real zeros of the function:
4x%5E4-21x%5E2-25
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
 

Hi,

finding the complex and real zeros of the function

4x%5E4-21x%5E2-25+=+4%28x%5E2%29%5E2+-21%28x%5E2%29+-+25

x%5E2+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+

x%5E2++=+%28-21+%2B-+sqrt%28+841+%29%29%2F%282%2A4%29+

x%5E2++=+%28-21+%2B-+29%29%2F%288%29+

   x^2 =  8/8 = 1   AND x^2 = -50/8 = -25/4 

  x = ± 1  And x = ± 2.5i