**NCERT Solutions for Maths Class 12 Exercise 9.4**

Hello Students. Welcome to **maths-formula.com**. In this post, you will find the complete** ****NCERT Solutions for Maths Class 12 Exercise 9.4**.

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Class 12th is a very crucial stage of your student’s life, since you take all important decisions about your career on this stage. Mathematics plays a vital role to take decision for your career because if you are good in mathematics, you can choose engineering and technology field as your career.

**NCERT Solutions for Maths Class 12 Exercise 9.4** helps you to solve each and every problem with step by step explanation which makes you strong in mathematics.

All the schools affiliated with CBSE, follow the NCERT books for all subjects. You can check your syllabus from **NCERT Syllabus for Mathematics Class 12**.

**NCERT Solutions for Maths Class 12 Exercise 9.4** are prepared by the experienced teachers of CBSE board. If you are preparing for JEE Mains and NEET level exams, then it will definitely make your foundation strong.

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**NCERT Solutions for Maths Class 12 Exercise 9.1**

**NCERT Solutions for Maths Class 12 Exercise 9.2**

**NCERT Solutions for Maths Class 12 Exercise 9.3**

**NCERT Solutions for Maths Class 12 Exercise 9.5**

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**NCERT Solutions for Maths Class 12 Exercise 9.6**

**NCERT Solutions for Maths Class 12 Exercise 9.4**

**For each of the
following differential equation in Exercises 1 to 10, find the general
solution:**

**Maths Class
12 Ex 9.4 Question 1.**

**Solution:**

**Maths Class 12 Ex 9.4 Question 2.**

**Maths Class 12 Ex 9.4 Question 3.**

**Maths Class 12 Ex 9.4 Question 4.**

sec² *x* tan *y dx* + sec² *y* tan *x dy* = 0

**Solution:**

We have, sec² *x* tan *y dx* + sec² *y* tan *x dy* = 0

**Maths Class
12 Ex 9.4 Question 5.**

**Maths Class 12 Ex 9.4 Question 6.**

**Maths Class 12 Ex 9.4 Question 7.**

*y* log *y
dx* – *x dy* = 0

**Solution:**

We
have, *y* log *y
dx* – *x dy* = 0

*dy*/*y* log *y* = *dx*/*x * … (i)

Integrating equation (i) on both sides, we get

**Maths Class
12 Ex 9.4 Question 8.**

**Maths Class 12 Ex 9.4 Question 9.**

**Maths Class 12 Ex 9.4 Question 10.**

**For each of the
following differential equations in Exercises 11 to 14, find a particular solution
satisfying the given condition: **

**Maths Class
12 Ex 9.4 Question 11.**

**Maths Class 12 Ex 9.4 Question 12.**

**Maths Class 12 Ex 9.4 Question 13.**

**Maths Class 12 Ex 9.4 Question 14.**

**Maths Class 12 Ex 9.4 Question 15.**

Find the equation
of the curve passing through the point (0, 0) and whose differential equation
is *y*’ = *e ^{x}* sin

*x*.

**Maths Class
12 Ex 9.4 Question 16.**

For the differential equation , find the solution curve passing through the point (1, –1).

**Solution:**

The given
differential equation is

or *xy dy *= (*x* + 2) (*y* + 2) *dx*

**Maths Class 12 Ex 9.4 Question 17.**

Find the equation
of a curve passing through the point (0, –2) given that at any point (*x*, *y*)
on the curve, the product of the slope of its tangent and *y*-coordinate of the point is equal to the *x*-coordinate of the point.

**Solution:**

**Maths Class
12 Ex 9.4 Question 18.**

At any point (*x*, *y*)
of a curve, the slope of the tangent is twice the slope of the line segment joining
the point of contact to the point (–4, –3). Find the equation of the curve
given that it passes through (–2, 1).

**Solution:**

Slope of the
tangent to the curve = *dy*/*dx*

Slope of the line joining (*x*, *y*) and (–4, –3)

**Maths Class
12 Ex 9.4 Question 19.**

The volume of a
spherical balloon being inflated changes at a constant rate. If initially its
radius is 3 units and after 3 seconds it is 6 units. Find the radius of balloon
after *t* seconds.

**Solution:**

Let v be volume
of the balloon.

**Maths Class
12 Ex 9.4 Question 20.**

In a bank,
principal increases continuously at the rate of *r*% per year. Find the value of *r*
if Rs 100 double itself in 10 years (log 2 = 0.6931).

**Solution:**

Let P be the
principal at any time *t*.

According to the problem,

**Maths Class
12 Ex 9.4 Question 21.**

In a bank,
principal increases continuously at the rate of 5% per year. An amount of Rs
1000 is deposited with this bank, how much will it worth after 10 years (*e*^{0.5} = 1.648).

**Solution:**

**Maths Class
12 Ex 9.4 Question 22.**

In a culture, the
bacteria count is 1,00,000. The number is increased by 10% in 2 hours. In how
many hours will the count reach 2,00,000, if the rate of growth of bacteria is
proportional to the number present?

**Solution:**

Let *y* denote the number of bacteria at any
instant *t*.

According to the
question,

**Maths Class
12 Ex 9.4 Question 23.**

The general solution of the differential equation is

(A) e^{x} + e^{-y} = C

(B) e^{x} + e^{y} = C

(C) e^{-x} + e^{y} = C

(D) e^{-x} + e^{-y} = C

**NCERT Solutions for Maths Class 12 Exercise 9.1**

**NCERT Solutions for Maths Class 12 Exercise 9.2**

**NCERT Solutions for Maths Class 12 Exercise 9.3**

**NCERT Solutions for Maths Class 12 Exercise 9.5**

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**NCERT Solutions for Maths Class 12 Exercise 9.6**