Question
Question: If the roots of the equation \(x^{2} - 2ax + a^{2} + a - 3 = 0\) are real and less than 3, then...
If the roots of the equation x2−2ax+a2+a−3=0 are real and less than 3, then
A
a< 2
B
2≤a≤3
C
3<a≤4
D
a>4
Answer
a< 2
Explanation
Solution
Given equation is x2−2ax+a2+a−3=0
If roots are real, then D≥0
⇒ 4a2−4(a2+a−3)≥0 ⇒ −a+3≥0 ⇒ a−3≤0 ⇒ a≤3
As roots are less than 3, hence f(3)>0
9−6a+a2+a−3>0 ⇒ a2−5a+6>0 ⇒ (a−2)(a−3)>0 ⇒ a<2,a>3. Hence a < 2 satisfy all the conditions.