The number of integral values of for which the quadratic expression, , is always positive, is :
- (A)3
- (B)8
- (C)7✓ Correct
- (D)6
Answer: (C)
Solution
For to stay positive for all real , the leading coefficient must be positive, , and the discriminant negative. The discriminant condition simplifies to , i.e. , roughly . Combined with , the integer values are seven of them.
JEE Main · 2019 · 12 Jan 2019 · Shift 2 · Single correct option