If the product of the zeroes of the quadratic polynomial p(x)=ax2−6x−6 is 4 , then find the value of a. Also, find the sum of the zeroes of the polynomial.
Q. If the product of the zeroes of the quadratic polynomial p(x)=ax2−6x−6 is 4 , then find the value of a. Also, find the sum of the zeroes of the polynomial.
Denote the zeroes: Let's denote the zeroes of the polynomial p(x)=ax2−6x−6 as α (alpha) and β (beta). According to Vieta's formulas, for a quadratic polynomial ax2+bx+c, the product of the roots is given by ac and the sum of the roots is given by −ab.
Use Vieta's formula: Given that the product of the zeroes (αβ) is 4, we can write the equation using Vieta's formula: αβ=ac. In our case, c=−6 and we are given αβ=4. So we have −a6=4.
Solve for a: Solving for a, we multiply both sides by a to get −6=4a. Then, we divide both sides by 4 to find the value of a: a=−6/4=−3/2.
Find sum of zeroes: Now, we need to find the sum of the zeroes (α+β). Using Vieta's formula again, we have α+β=−ab. In our case, b=−6 and we have already found a=−23. So we have α+β=−(−6)/(−23).
Simplify the expression: Simplifying the expression for the sum of the zeroes, we get α+β=(−23)6=6×(−32)=−4.