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Solve for x (complex solution)
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\frac{1}{4}x^{2}=-2
Subtract 2 from both sides. Anything subtracted from zero gives its negation.
x^{2}=-2\times 4
Multiply both sides by 4, the reciprocal of \frac{1}{4}.
x^{2}=-8
Multiply -2 and 4 to get -8.
x=2\sqrt{2}i x=-2\sqrt{2}i
The equation is now solved.
\frac{1}{4}x^{2}+2=0
Quadratic equations like this one, with an x^{2} term but no x term, can still be solved using the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}, once they are put in standard form: ax^{2}+bx+c=0.
x=\frac{0±\sqrt{0^{2}-4\times \frac{1}{4}\times 2}}{2\times \frac{1}{4}}
This equation is in standard form: ax^{2}+bx+c=0. Substitute \frac{1}{4} for a, 0 for b, and 2 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{0±\sqrt{-4\times \frac{1}{4}\times 2}}{2\times \frac{1}{4}}
Square 0.
x=\frac{0±\sqrt{-2}}{2\times \frac{1}{4}}
Multiply -4 times \frac{1}{4}.
x=\frac{0±\sqrt{2}i}{2\times \frac{1}{4}}
Take the square root of -2.
x=\frac{0±\sqrt{2}i}{\frac{1}{2}}
Multiply 2 times \frac{1}{4}.
x=2\sqrt{2}i
Now solve the equation x=\frac{0±\sqrt{2}i}{\frac{1}{2}} when ± is plus.
x=-2\sqrt{2}i
Now solve the equation x=\frac{0±\sqrt{2}i}{\frac{1}{2}} when ± is minus.
x=2\sqrt{2}i x=-2\sqrt{2}i
The equation is now solved.