Observe the given equation.
Step 2 :
Find the value of discriminant(D) by applying the formula D = b2 - 4ac.
Step 3 :
If the value of discriminant(D) is less than zero, write "roots does not exist (or) imaginary. And if discriminant is greater or equal to zero, then find the roots of an equation by applying the formula x1= $\frac{-b + \sqrt{D}}{2a}$ and x2 = $\frac{-b - \sqrt{D}}{2a}$
Calculate the roots of the equation: x2 + 6x + 8 = 0?
Step 1 :Given equation: x2 + 6x + 8 = 0
So, a = 1, b = 6 and c =8
Step 2 :Discriminant(D) = b2 - 4ac
= (6)2 - 4(1)(8)
= 36 - 32
= 4
Step 3 :x1= $\frac{-b + \sqrt{D}}{2a}$
x1= $\frac{-6 + \sqrt{4}}{2(1)}$
x1= $\frac{-6 + 2}{2}$
x1= $\frac{-4}{2}$
x1 = -2
and x2 = $\frac{-b - \sqrt{D}}{2a}$
and x2 = $\frac{-6 - \sqrt{4}}{2(1)}$
and x2 = $\frac{-6 - 2}{2}$
and x2 = $\frac{- 8}{2}$
and x2 = -4
Answer :x1 = -2 and x2 = -4
Calculate the roots of the equation: x2 + 9x + 8?
Step 1 :Given equation: x2 + 9x + 8 = 0
So, a = 1, b = 9 and c =8
Step 2 :Discriminant(D) = b2 - 4ac
= (9)2 - 4(1)(8)
= 81 - 32
= 49
Step 3 :x1= $\frac{-b + \sqrt{D}}{2a}$
x1= $\frac{-9 + \sqrt{49}}{2(1)}$
x1= $\frac{-9 + 7}{2}$
x1= $\frac{-2}{2}$
x1 = -1
and x2 = $\frac{-b - \sqrt{D}}{2a}$
and x2 = $\frac{-9 - \sqrt{49}}{2(1)}$
and x2 = $\frac{-9 - 7}{2}$
and x2 = $\frac{-16}{2}$
and x2 = -8
Answer :x1 = -1 and x2 = -8