Question

Form a quadratic polynomial whose zeroes are 3-√3/5 and 3+√3/5?​

Answer 1

x^2 -6x + 222/25

Explanation:

If the zeros are as above, then ;

x = 3-√3/5 or x = 3 + √3/5

Firstly, let’s represent √3/5 by b

Thus;

The two roots are ;

x = 3-b or x = 3 + b

so;

x+ b -3 and x -3-b

The quadratic equation is the product of the two

(x + b-3)(x - b -3)

x(x - b-3) + b(x -b -3) -3(x - b -3)

= x^2 -bx -3x + bx -b^2 -3b -3x + 3b + 9

Collect like terms and we are left with;

x^2 -6x -b^2 + 9

So let’s put back b = √3/5

x^2 -6x -(√3/5)^2 + 9

x^2 -6x -3/25 + 9

x^2 -6x + 222/25