a) The quadratic 3x^2-12x-11 can be written in the form 3(x+a)^2+b. Find the values of a and b. b) Given that the solutions of the equation 3x^2-12x-11=0 can be written as c ± √d, where c and d are rational numbers. Find the values of c and d answer for d as a fraction in it's simplest form

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Answer:

Step-by-step explanation:

a) 3x^2-12x-11=3*x^2-3*2*2*x+3*4-23=3*(x^2-2*2x+2^2)-23=3*(x-2)^2-23

so  a= -2 ,b= -23

b) x1=[12+V(12^2-4*3* -11)]/6=12/6+V(144+132)/6=2+2/6V69=2+1/3V69=

2+V69/9=2+V23/3

c=2, d= 23/3

a) The value of a and b from the expression are -2 and -23 respectively.

b) The value of c and d are 2 and 23/3 respectively'

a) Given the quadratic function [tex]3x^2-12x-11[/tex], writing the equation in the form [tex]3(x+a)^2+b[/tex] using the completing the square method.

[tex]3x^2-12x-11=0\\x^2-\frac{12}{3}x-\frac{11}{3} =0\\x^2-4x-\frac{11}{3} =0\\(x^2-4x+4)-4-\frac{11}{3}=0\\(x-2)^2-\frac{23}{3} =0\\3(x-2)^2-23=0[/tex]

Compare the result with [tex]3(x+a)^2+b[/tex];

a = -2

b = -23

Hence the value of a and b from the expression are -2 and -23 respectively.

b) Given the quadratic equation [tex]3x^2-12x-11=0[/tex] using the general formula to factorize the equation;

[tex]x=\frac{-b\pm \sqrt{b^2-4ac} }{2a} \\x=\frac{-(-12)\pm \sqrt{(-12)^2-4(3)(-11)} }{2(3)} \\x=\frac{12\pm \sqrt{144+132} }{6} \\x=\frac{12\pm\sqrt{276} }{6} \\x=2\pm\sqrt{\frac{276}{36} }\\x=2\pm\sqrt{\frac{23}{3} } }[/tex]

Compared with c ± √d, the value of c and d are 2 and 23/3 respectively.

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