JEE Main202227 Jun 2022Morning ShiftMathematicsLimitsActual
Let a be an integer such that lim x → 7 18 - 1 - x x - 3 a exists, where t is greatest integer ≤ t . Then a is equal to
Options
- A- 2
- B6
- C- 6
- D- 7
Correct answer
C. - 6
Step-by-step solution
Since lim x → 7 18 - 1 - x x - 3 a exists a ∈ 𝕀 ∴ L . H . L   =   R . H . L ⇒ lim h → 0 18 - - 6 7 - h - 3 a = lim h → 0 18 - - 7 7 + h - 3 a ⇒ lim h → 0 24 7 - 3 a + - h = lim h → 0 25 7 - 3 a + h ⇒ 24 6 - 3 a = 25 7 - 3 a ⇒ a = - 6