Question
Question: If x<sup>2</sup> – 4x + log<sub>1/2</sub>a = 0 does not have two distinct real roots, then maximum v...
If x2 – 4x + log1/2a = 0 does not have two distinct real roots, then maximum value of a is
A
¼
B
1/ 16
C
–1/4
D
None
Answer
1/ 16
Explanation
Solution
Since x2 – 4x + log1/2a = 0 does not have two distinct real roots, discriminant ≤ 0
⇒ 16 – 4 log1/2 a ≤ 0 ⇒ log1/2 a ≥ 4 ⇒ a ≤ 1/16