MP Board Class 12th Maths Important Questions Chapter 5 Continuity and Differentiability
MP Board Class 12th Maths Important Questions Chapter 5 Continuity and Differentiability
MP Board Class 12th Maths Important Questions Chapter 5 Continuity and Differentiability
Important Questions
Short Answer Type Questions
Question 1.
Find all the points of discontinuity of f, when f is defined as:

Solution:
For x< 2, f(x) = 2x + 3 is polynomial function.
Hence, for x < 2, f(x) is continuous function. For x > 2, f(x) = 2x – 3 is polynomial function.
Hence, x > 2, f(x) is continous.
Now, we shall examine the continuty of f(x) at x = 2 only.
Put x = 2 + h,
When x → 2, then h → 0

Question 2.
Find all the points of discontunity of f, when f is defined as follow:

Question 3.
Examine the continuty of function f(x) at point x = 0?

Question 4.
Function f is defined as:

Then prove that function f is continous function for all points except x = 4?
Solution:

Hence, for x = 4 the function f(x) is dicontinous
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When x < 4 then f(x) = -1 which is constant function Hence, it is continous function when x > 4 then f(x) = 1 which is constant function.
Hence, it is continous function
The given functions f is continous at all points except x = 4. Proved.
Question 5.
Find the value of k for which the function


Question 6.
Find the value of k, if function

Question 7.
Function f is continous at x = 0:

Question 8.
Find the relationship between a and b so the following function f defined by:

Question 9.
Prove that the funcion f(x) = |x – 1|, x ∈ R is not differentiable at x = 1? (NCERT)
Solution:
Given:

Question 10.
Show that the function:

Solution:
We know that:
RHD =

From the above, it is clear that,
LHD at x = 2 ≠ RHD at x = 2
∴ f(x) is not differentiable at x = 2. Proved.
Question 11.
Determine the function of defined by

Objective Type Questions:
Question 1.
Choose the correct answer:

Question 3.
The value of
(x3 + sin x2) is to be:
(a) 3x2 + cos x2
(b) 3x2 + x sin x2
(c) 3x2 + 2x cos x2
(d) 3x2 + x cos x2
Answer:
(c) 3x2 + 2x cos x2
Question 4.
The value of
ax is to be:
(a) ax
(b) ax loga e
(c) ax loge a
(d) ![]()
Answer:
(c) ax loge a
Question 5.
If y = 500e7x + 600e-7x, then the value of
will be:
(a) 45 y
(b) 47 y
(c) 49 y
(d) 50 y
Answer:
(c) 49 y
Question 2.
Fill in the blanks:
- Differential coefficient of cos x0 w.r.t x is ……………………………..
- Differential coefficient of elogea w.r.t x is ……………………………….
- Differential coefficient of loge a w.r.t x is ………………………………
- Differential coefficient of ax w.r.t x is ……………………………….
- Differential coefficient of sin 3x w.r.t x is ……………………………….
- If y = sin-1
, then
= ……………………………… - Differential coefficient of sin x w.r.t. cos x is …………………………………..
- The value of
(log tan x) is ……………………………………… - Differential coefficient of log (log sin x) ………………………………
Answer:

Question 3.
Write True/False:
- Any function f(x) is said to be differentiatiable at any point x = a when Lf'(a) ≠ Rf'(a)?
- Differential coefficient of sec-1a w.r.t x is 0?
- Every differentiatiable function is continous?
- Differential coefficient of a2x is a2x logea?
Answer:
- Flase
- False
- True
- Flase
Question 4.
Match the Column:

Answer:
- (d)
- (e)
- (a)
- (f)
- (h)
- (g)
- (c)
- (b)
Question 5.
Write the answer in one word/sentence:

