Step-by-step explanation:
The discriminant of the quadratic equation
:

If Δ < 0, then the equation has two complex roots 
If Δ = 0, then the equation has one repeated root ![x=\dfrac{-b}{2a}[/tex If Δ > 0, then the equation has two discint roots [tex]x=\dfrac{-b\pm\sqrt\Delta}{2a}](https://tex.z-dn.net/?f=x%3D%5Cdfrac%7B-b%7D%7B2a%7D%5B%2Ftex%20%3C%2Fp%3E%3Cp%3EIf%20%CE%94%20%3E%200%2C%20then%20the%20equation%20has%20two%20discint%20roots%20%5Btex%5Dx%3D%5Cdfrac%7B-b%5Cpm%5Csqrt%5CDelta%7D%7B2a%7D)




Answer: 8 pi
Step-by-step explanation: So we know that area of a circle is pi times r^2 so if we reverse that formula it would be square root of 16 pi which would be 4 pi and divide by pi so the radius is 4. And we know that the formula for circumference is 2 times pi times r, so 2 times 4 times pi is 8 pi. 8 pi is the cIrcumference! :)
You would divide the rate