NCERT Solutions for Class 12 Maths Chapter 5 – Continuity and Differentiability Ex 5.7
Page No 183:
Question 1:
Find the second order derivatives of the function.
Answer:
Let
Then,

Question 2:
Find the second order derivatives of the function.
Answer:
Let
Then,

Question 3:
Find the second order derivatives of the function.
Answer:
Let
Then,

Question 4:
Find the second order derivatives of the function.
Answer:
Let
Then,

Question 5:
Find the second order derivatives of the function.
Answer:
Let
Then,

Question 6:
Find the second order derivatives of the function.
Answer:
Let
Then, 

Question 7:
Find the second order derivatives of the function.
Answer:
Let
Then,

Question 8:
Find the second order derivatives of the function.
Answer:
Let
Then,

Question 9:
Find the second order derivatives of the function.
Answer:
Let
Then,

Question 10:
Find the second order derivatives of the function.
Answer:
Let
Then,

Question 11:
If
, prove that
Answer:
It is given that,
Then,

Hence, proved.
Page No 184:
Question 12:
If
find
in terms of y alone.
Answer:
It is given that,
Then,

Question 13:
If
, show that
Answer:
It is given that,
Then,

Hence, proved.
Question 14:
If
show that
Answer:
It is given that,
Then,

Hence, proved.
Question 15:
If
, show that
Answer:
It is given that,
Then,

Hence, proved.
Question 16:
If
, show that
Answer:
The given relationship is

Taking logarithm on both the sides, we obtain
Differentiating this relationship with respect to x, we obtain

Hence, proved.
Question 17:
If
, show that
Answer:
The given relationship is
Then,

Hence, proved.