Question

find zeros of 3x2+x+18​

Answer 1

Solving 3x2+x+8 = 0 by the Quadratic Formula .

According to the Quadratic Formula, x , the solution for Ax2+Bx+C = 0 , where A, B and C are numbers, often called coefficients, is given by :

X = - B ± √ B2-4AC /2A

In our case, A = +3

B = +1

C = +8

Accordingly, B2 - 4AC

=> 1 - (+216)

=> -215

Applying the quadratic formula :

X= 1 ± √ -215 / 6

√ 215 , rounded to 4 decimal digits, is 14.6628

So now we are looking at:

x = ( 1 ± 14.6628 ) / 6

Two real solutions:

x =(1+√-215)/6= 2.863

or:

x =(1-√-215)/6=-0.8633

Two solutions were found :

x =(1-√-215)/6=-0.8633

x =(1+√-215)/6= 2.863

Hope it helps!☺