To find the value of A for which the difference of the squares of the roots of the quadratic equation x2−(A−3)x−(A−2)=0 is zero, we start by noting that the difference of the squares of the roots r1 and r2 can be expressed as:
r12−r22=(r1−r2)(r1+r2)
For this difference to be zero, either r1−r2=0 (which means the roots are equal) or r1+r2=0.
Using Vieta's formulas, we know:
- The sum of the roots r1+r2=A−3
- The product of the roots r1r2=−(A−2)
For the roots to be equal, the discriminant must be zero:
D=b2−4ac=(A−3)2−4(1)(−(A−2))=0
Expanding this gives:
(A−3)2+4(A−2)=0
Expanding further:
A2−6A+9+4A−8=0
Combining like terms:
A2−2A+1=0
Factoring:
(A−1)2=0
Thus, A−1=0 implies A=1.
Therefore, the value of A for which the difference of the squares of the roots is zero is:
1