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QJEEM19Ma91c5: JEE Main 2019 Mathematics - Class 11 JEEM19Ma91c5 Solution: The number of integral values of m for which the equation (1 +…
The number of integral values of m for which the equation
(1 + m2 )x2 – 2(1 + 3m)x + (1 + 8m) = 0 has no real root is :
(1 + m2 )x2 – 2(1 + 3m)x + (1 + 8m) = 0 has no real root is :
Multiple Choice Options
- A 2
- B infinitely many
- C 1
- D 3
Step-by-Step Verified Solution
(1 + m2 )x2 – 2(1 + 3m)x + (1 + 8m) = 0
Given equation has no real solution,
Discriminant (D) < 0
4(1 + 3m)2 - 4(1 + m2)(1 + 8m) < 0
4[9m2 + 6m + 1 - 8m - 1 - 8m3 - m2] < 0
-8m3 + 8m2 - 2m < 0
-2m(4m2 - 4m + 1) < 0
m(2m - 1)2 > 0
m > 0 and m
So we can say number of integral values of m are infinitely many.
Given equation has no real solution,
Discriminant (D) < 0
4(1 + 3m)2 - 4(1 + m2)(1 + 8m) < 0
4[9m2 + 6m + 1 - 8m - 1 - 8m3 - m2] < 0
-8m3 + 8m2 - 2m < 0
-2m(4m2 - 4m + 1) < 0
m(2m - 1)2 > 0
m > 0 and m
So we can say number of integral values of m are infinitely many.