SOLUTION: Solve over the set of complex numbers. Use completing the square. 8x^2-x-1=0 (the x on first term is squared) Thank you

Question 215532: Solve over the set of complex numbers. Use completing the square.
8x^2-x-1=0 (the x on first term is squared)
Thank you
Answer by ankor@dixie-net.com(22740) (Show Source): You can put this solution on YOUR website!
8x^2 - x - 1 = 0
:
8x^2 - x = 1
:
The coefficient of x^2 has to be 1, divide all terms by 8
x^2 - x =
:
x^2 - x + ___ =
Find the 3rd term that completes the square, divide the coefficient of x by 2
then square it; that would be (-1/16)^2, which is , add to both sides
x^2 - x + = +
x^2 - x + = +
x^2 - x + =
which is:
(x - )^2 =
Find the square root of both sides
x - = +/-
:
We can extract the square root of (1/256) which is 1/16
x - = +/-
:
Add 1/16 to both sides
x = +/-
;
From this we can write the two solutions as:
x =
and
x =
;
Did you understand what went on here? Let me know, ankor@att.net
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