Solve 3.5=1/2*x^2

$$3.5 = \frac { 1 } { 2 } \times x ^ { 2 }$$

Solve for x

$$x=\sqrt{7}\approx 2.645751311$$

$$x=-\sqrt{7}\approx -2.645751311$$

Steps by Finding Square Root

Multiply both sides by 2, the reciprocal of \frac{1}{2}.

$$3.5\times 2=x^{2}$$

Multiply 3.5 and 2 to get 7.

$$7=x^{2}$$

Swap sides so that all variable terms are on the left hand side.

$$x^{2}=7$$

Take the square root of both sides of the equation.

$$x=\sqrt{7} x=-\sqrt{7}$$

Steps Using the Quadratic Formula

Multiply both sides by 2, the reciprocal of \frac{1}{2}.

$$3.5\times 2=x^{2}$$

Multiply 3.5 and 2 to get 7.

$$7=x^{2}$$

Swap sides so that all variable terms are on the left hand side.

$$x^{2}=7$$

Subtract 7 from both sides.

$$x^{2}-7=0$$

This equation is in standard form: ax^{2}+bx+c=0. Substitute 1 for a, 0 for b, and -7 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.

$$x=\frac{0±\sqrt{0^{2}-4\left(-7\right)}}{2}$$

Square 0.

$$x=\frac{0±\sqrt{-4\left(-7\right)}}{2}$$

Multiply -4 times -7.

$$x=\frac{0±\sqrt{28}}{2}$$

Take the square root of 28.

$$x=\frac{0±2\sqrt{7}}{2}$$

Now solve the equation x=\frac{0±2\sqrt{7}}{2} when ± is plus.

$$x=\sqrt{7}$$

Now solve the equation x=\frac{0±2\sqrt{7}}{2} when ± is minus.

$$x=-\sqrt{7}$$

The equation is now solved.

$$x=\sqrt{7} x=-\sqrt{7}$$