Solve for x
x=\sqrt{e}\approx 1.648721271
x=-\sqrt{e}\approx -1.648721271
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x=\sqrt{e} x=-\sqrt{e}
Take the square root of both sides of the equation.
x^{2}=e
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^{2}-e=e-e
Subtract e from both sides of the equation.
x^{2}-e=0
Subtracting e from itself leaves 0.
x=\frac{0±\sqrt{0^{2}-4\left(-e\right)}}{2}
This equation is in standard form: ax^{2}+bx+c=0. Substitute 1 for a, 0 for b, and -e for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{0±\sqrt{-4\left(-e\right)}}{2}
Square 0.
x=\frac{0±\sqrt{4e}}{2}
Multiply -4 times -e.
x=\frac{0±2\sqrt{e}}{2}
Take the square root of 4e.
x=\sqrt{e}
Now solve the equation x=\frac{0±2\sqrt{e}}{2} when ± is plus.
x=-\sqrt{e}
Now solve the equation x=\frac{0±2\sqrt{e}}{2} when ± is minus.
x=\sqrt{e} x=-\sqrt{e}
The equation is now solved.
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