SOLUTION: xsquared+x+8=0

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Question 86229: xsquared+x+8=0
Answer by praseenakos@yahoo.com(507) About Me  (Show Source):
You can put this solution on YOUR website!
Question:

+x%5E2+%2B+x+%2B+8+=+0+


This is a quadratic equation.

You can solve this equation using quadratic formula...
which is given as,


For the quadratic equation , +ax%5E2+%2B+bx+%2B++c+=+0+

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

Comparing the standard equation and the given equation ....you have,

a = 1, b = 1 and c= 8


so the solution is given by,


x+=+%28-1+%2B-+sqrt%28+1%5E2-4%2A1%2A8+%29%29%2F%282%2A1%29+


x+=+%28-1+%2B-+sqrt%28+1-+32+%29%29%2F%282%29+


==> x+=+%28-1+%2B-+sqrt%28+-31+%29%29%2F%282%29+


Since square root of (-31) is not possible, the solution will be an imaginary number...

==> x+=+%28-1+%2B-+++sqrt%28+%28i%29%5E2%2A+31+%29%29%2F%282%29+


==> x+=+%28-1+%2B-++i+sqrt%28+31+%29%29%2F%282%29+


==> x+=+%28-1+%2B-+%28i+%2A+5.57%29%29%2F%282%29+

So the solution is,

+x+=+%28-1+%2B+i+%2A+5.57%29%2F2 or +x+=+%28-1+-+i%2A+5.57%29%2F2


That is the solution is a complex number..


Hope you found the explanation useful....
Regards.

Praseena.