Solve 400=I^250

$$400 = I ^ { 2 } 50$$

Solve for I

$$I=2\sqrt{2}\approx 2.828427125$$

$$I=-2\sqrt{2}\approx -2.828427125$$

Steps by Finding Square Root

Divide both sides by 50.

$$\frac{400}{50}=I^{2}$$

Divide 400 by 50 to get 8.

$$8=I^{2}$$

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

$$I^{2}=8$$

Take the square root of both sides of the equation.

$$I=2\sqrt{2} I=-2\sqrt{2}$$

Steps Using the Quadratic Formula

Divide both sides by 50.

$$\frac{400}{50}=I^{2}$$

Divide 400 by 50 to get 8.

$$8=I^{2}$$

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

$$I^{2}=8$$

Subtract 8 from both sides.

$$I^{2}-8=0$$

This equation is in standard form: ax^{2}+bx+c=0. Substitute 1 for a, 0 for b, and -8 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.

$$I=\frac{0±\sqrt{0^{2}-4\left(-8\right)}}{2}$$

Square 0.

$$I=\frac{0±\sqrt{-4\left(-8\right)}}{2}$$

Multiply -4 times -8.

$$I=\frac{0±\sqrt{32}}{2}$$

Take the square root of 32.

$$I=\frac{0±4\sqrt{2}}{2}$$

Now solve the equation I=\frac{0±4\sqrt{2}}{2} when ± is plus.

$$I=2\sqrt{2}$$

Now solve the equation I=\frac{0±4\sqrt{2}}{2} when ± is minus.

$$I=-2\sqrt{2}$$

The equation is now solved.

$$I=2\sqrt{2} I=-2\sqrt{2}$$