Please help!!

Question

Find the zeros of each function by using the quadratic formula.

F(x) = x2(squared) +10x+9

g(x) = 2x2(squared) +4x -12

h(x)= 3x2(squared)-3x+3/4

f(x)= x2(squared)+2x-3 

g(x)=2x2(squared)+3x+1

g(x)= x2(squared)+5x-3

 

 

 

Answer 1

A quadratic equation always has the form ax² + bx + c = f(x)

where the letters a,b,c are the coefficients of the respective powers of x.

 

Since all the functions you posted are very similar, I will only show the 2nd answer and leave the rest for you to try. I you still don't get the answers, let me know. 

 

g(x) = 2x² + 4x - 12

f(x)  = ax² + bx + c

 

Quadratic formula :

 

x = [- b        +/-          sqrt(b² - 4ac)]            /2a

x = [- 4        +/-          sqrt(4² - 4(2)(-12))]    /2(2)

 

x = [-4  +/-  sqrt(16+96)]/4

x = [-4  +/-  sqrt(112)]4

x = [-4  +/-  10.6]/4

 

+/- means that there are 2 possible values of x

 

 

x = [-4 + 10.6]/4                        or             x = [-4 - 10.6]/4

x = 1.646                                   or             x = -3.646

 

 

 

 

Answer 2

I shall do one as a model. You can follow the model and do the remainder.

 

F(x) = x² + 10x + 9, a = 1, b = 10, c = 9

 

x = {-b ±√(b² - 4ac)} / 2a

x = {-10 ±√(10² - 4 · 1 · 9)} / (2 · 1)

x = {-10 ±√(100 + 36)} / 2

x = {-10 ±√136} / 2

x = (-10 ±2√34) / 2

x = -5 ± √34