Find the values of the coefficients b and c in the quadratic equation 3x2+bx+c if the sum and product of the roots of this equation are respectively 7/3 and 13/3.

Respuesta :

Answer:

a = 3

b = -7

c = 13

Step-by-step explanation:

[tex]\sf{given \ equation: 3x^2+bx+c[/tex]

[tex]\sf{sum \ of \ roots :\sf\frac{7}{3}[/tex]

[tex]\sf{product \ of \ the \ roots:\frac{13}{3}[/tex]

  • a = 3
  • b = b
  • c = c

[tex]\sf{sum \ of \ roots \ = -\dfrac{coefficient \of \ x}{coefficient \ of \ x^2} }[/tex]

[tex]\sf \frac{-b}{3} = \frac{7}{3}[/tex]

[tex]\sf b = \frac{-7*3}{3}[/tex]

[tex]\sf b =- 7[/tex]

[tex]\sf{product \ of \ roots \ = \dfrac{constant \ term}{coefficient \ of \ x^2} }[/tex]

[tex]\sf{\frac{c}{3} =\frac{13}{3}[/tex]

[tex]\sf c = \frac{13*3}{3}[/tex]

[tex]\sf c = 13[/tex]

Therefore found that a = 3, b = -7, c = 13

Answer:

b = -7

c = 13

Step-by-step explanation:

[tex]3x^2+bx+c[/tex]

[tex]\textsf{sum of roots}=\dfrac{-b}{a}\\\\\textsf{product of roots}=\dfrac{c}{a}[/tex]

[tex]\textsf{Given sum of roots}=\dfrac73:[/tex]

[tex]\implies \dfrac{-b}{a}=\dfrac73[/tex]

[tex]\implies a=3, b=-7[/tex]

[tex]\textsf{Given product of roots}=\dfrac{13}{3}:[/tex]

[tex]\implies \dfrac{c}{a}=\dfrac{13}{3}[/tex]

[tex]\implies a=3, c=13[/tex]

Therefore,

[tex]3x^2-7x+13[/tex]

NB: The actual calculated roots are imaginary numbers as the function [tex]f(x)=3x^2-7x+13[/tex] does not intercept the x-axis