Answer:
Value of x using quadratic formula (x = -4) and (x = -5)
Step-by-step explanation:
Given:
Equation
x² + 9x + 20 = 0
Find:
Value of x using quadratic formula
Computation:
Quadratic formula = [-b±√b²-4ac] / 2a
Given equation;
x² + 9x + 20 = 0
a = 1 , b = 9 , c = 20
By putting value
[-9±√9²-4(1)(20)] / 2(1)
[-9±√81-80] / 2
[-9±√1] / 2
(-9 + 1) / 2 , (-9 - 1) / 2
-8 / 2 , 10 / 2
-4 , - 5
Value of x using quadratic formula (x = -4) and (x = -5)
You can calculate the arc lenght by using this formula:
arc length = 2π*r*(A/360) , where A=angle of the arc.
So for you it would be:
arc length = 2π*4*(72/360) = 5.03
I hope that helped.
