JEE Advanced2019MathematicsLimitsActual
Let F : R → R be a function. We say that f has: PROPERTY 1 if lim h → 0 ⁡ f h - f 0 h exists and is finite, and PROPERTY 2 if lim h → 0 ⁡ f h - f 0 h 2 exists and is finite. Then which of the following options is/are correct?
Options
- Af x = x x has PROPERTY 2
- Bf x = x 2 / 3 has PROPERTY 1
- Cf x = sin x has PROPERTY 2
- Df x = x has PROPERTY 1
Correct answer
B. f x = x 2 / 3 has PROPERTY 1
Step-by-step solution
A f x = x lim h → 0 h - 0 h = lim h → 0 h = 0 B f x = x 2 3 lim h → 0 h 2 3 - 0 h = lim h → 0 h 1 6 = 0 C f x = x x lim h → 0 h h - 0 h 2 = lim h → 0 h h = 1 , i f h → 0 + - 1 , i f h → 0 - Does not exist D f x = sin x lim h → 0 sin h - 0 h 2 = lim h → 0 1 h sin h h ⇒ does not exist