NTA Abhyas JEE Main2020MathematicsContinuity and DifferentiabilityPractice
If f x = 5 x + 4 tan x x x ≠ 0 k x = 0 , then f x is continuous at x = 0 for
Options
- Ak = 9
- Bk = - 1
- Cno values of k
- Dk = 2
Correct answer
C. no values of k
Step-by-step solution
lim x → 0 - f x = lim x → 0 - 5 x + 4 tan x x = lim x → 0 - 5 - x + 4 tan x x = lim x → 0 - - 5 x x + lim x → 0 - 4 tan x x = - 5 + 4 = - 1 and lim x → 0 + f x = lim x → 0 + 5 x + 4 tan x x = lim x → 0 + 5 x x + 4 tan x x = 5 + 4 = 9 lim x → 0 - f x ≠ lim x → 0 + f x ∴ f x is not continuous at x = 0 , for any value of k