Careers360 Logo
RD Sharma Class 12 Exercise 28.9 The Plane Solutions Maths - Download PDF Free Online

RD Sharma Class 12 Exercise 28.9 The Plane Solutions Maths - Download PDF Free Online

Edited By Lovekush kumar saini | Updated on Jan 25, 2022 11:55 AM IST

The RD Sharma solutions are the all in one problem solver for all the CBSE students who are preparing to appear for the board exams. The Class 12 RD Sharma chapter 28 exercise 28.9 solution is advised to go through while practicing the chapter ‘The Plane.’ It helps you to get a brief understanding of the concept while providing excellent examples that help you to understand better. The RD Sharma class 12th exercise 28.9 is the most recommended book by teachers for the students of CBSE as it matches the level of NCERT.

This Story also Contains
  1. RD Sharma Class 12 Solutions Chapter28 The Plane - Other Exercise
  2. The Plane Exercise: 28.9
  3. RD Sharma Chapter-wise Solutions

Also Read - RD Sharma Solutions For Class 9 to 12 Maths

RD Sharma Class 12 Solutions Chapter28 The Plane - Other Exercise

The Plane Exercise: 28.9

The Plane Exercise 28.9 Question 1

Answer : 4713
Hint :  Distance =|Ax1+By1+Cz1+D|A2+B2+C2
Given : Point (2i^j^4k^) from the plane vector r(3i^4j^+12k^)=9
Solution :
For the given plane
Vector, r(3i^4j^+12k^)=9
Cartesian form is
3x4y+12z=9
We can write as,
3x4y+12z9=0
The point given is (2i^j^4k^)
Which can be written as (2,1,4)
We know that
 Distance =|Ax1+By1+Cz1+D|A2+B2+C2 Distance =|(2×3)+(1×4)+(4×12)+(9)|32+(4)2+122
So we get,
=|6+4489|9+16+144
On further calculation
=|47|169
=4713 Units 

The Plane Exercise 28.9 Question 2

Answer : The given points are equidistant from the plane
Hint :  Distance =|Ax1+By1+Cz1+D|A2+B2+C2
Given :
Two points (i^j^+3k^) and (3i^+3j^+3k^), plane r(5i^+2j^7k^)+9=0
Solution :
Points given by the equation
a=i^j^+3k^,b=3i^+3j^+3k^
Plane given by the equation
r(5i^+2j^7k^)+9=0, where the normal is n=5i^+2j^7k^
We know, the distance of a from the plane rnd=0 Is given by
p=|and|n||
Distance of i^j^+3k^ from the plane
=|(i^j^+3k^)(5i^+2j^7k^)+9|5i^+2j^7k^||=978 Units 
And,
Distance of 3i^+3j^+3k^ from the plane
=|(3i^+3j^+3k^)(5i^+2j^7k^)+9|5i^+2j^7k^||
=978 Units
The point i^j^+3k^and3i^+3j^+3k^ are equidistant from the plane
r(5i^+2j^7k^)+9=0

The Plane Exercise 28.9 Question 3

Answer : The answer of the given question is 3 units
Hint : P=|ax1+by1+cz1+da2+b2+c2|
Given :
Point A(2,3,5)
Plane x+2y2z9=0
Solution :
We know, the distance of point (x1,y1,z1) from the plane
ax+by+cz+d=0 Is given by
P=|ax1+by1+cz1+da2+b2+c2|
Putting the necessary values
Distance of the plane from A=|1×2+2×3+(2)×(5)912+22+(2)2|=3 Units 
Hence the distance of the plane (2,3,5) from the plane x+2y2z9=0 is 3 units

The Plane Exercise 28.9 Question 4

Answer : The answer of the given question is x+2y2z+4=0,x+2y2z8=0
Hint :
P=|ax1+by1+cz1+da2+b2+c2|
Given : Plane: x+2y2z+8=0, which are at a distance of 2 units from the point (2,1,1)
Solution :
The planes are parallel to x+2y2z+8=0 they must be of the form
x+2y2z+θ=0
We know, the distance of point (x1,y1,z1) from the plane ax+by+cz+d=0 given by
P=|ax1+by1+cz1+da2+b2+c2|
According to the question, the distance of the plane from (2,1,1) is 2 units
|1×2+2×1+(2)×(1)+θ12+22+(2)2|=2|2+θ3|=2
2+θ3=2 Or 2+θ3=2θ=4 Or θ=8
Hence the required planes are
x+2y2z+4=0x+2y2z8=0

The Plane Exercise 28.9 Question 5

Answer: The answer of the given question is that the points are equidistant from the plane
Hint :
P=|ax1+by1+cz1+da2+b2+c2|
Given :
Points A(1,1,1) and B(3,0,1)
Plane p=3x+4y12z+13=0
Solution :
We know that, the distance of points (x1,y1,z1) from the plane p=ax+by+cz+d=0 Is given by
Distance of (1,1,1) from the plane =|3×1+4×1+(12)×1+1332+42+(12)2|=813 Units 
Distance of (3,0,1) from the plane =|3×(3)+4×0+(12)×1+1332+42+(12)2|=813 Units 
The points (1,1,1)&(3,0,1) are equidistant from the plane 3x+4y12z+13=0

The Plane Exercise 28.9 Question 6

Answer : The answer of the given question are x2y+2z+2=0,x2y+2z4=0
Hint :
P=|ax1+by1+cz1+da2+b2+c2|
Given :
x2y+2z3=0, Point (1,1,1)
Solution :
Since the planes are parallel to x2y+2z3=0 they must be of the form x2y+2z+θ=0
We know, the distance of point (x1,y1,z1) from the plane p:ax+by+cz+d=0 is given by
P=|ax1+by1+cz1+da2+b2+c2|
According to the question, the distance of the plane from (1,1,1) is 1 Unit
|1×1+(2)×1+2×1+θ12+(2)2+22|=1|1+θ3|=1
1+θ3=1 Or 1+θ3=1θ=2 Or 4
The required planes are
x2y+2z+2=0&x2y+2z4=0

The Plane Exercise 28.9 Question 7

Answer : The answer of the given question is 5 Unit
Hint :
P=|ax1+by1+cz1+da2+b2+c2|
Given :
Points : A(2,3,5)
Plane : z=0
Solution :
We know, the distance of point (x1,y1,z1) from the plane
p:ax+by+cz+d=0 Is given by
P=|ax1+by1+cz1+da2+b2+c2|
Putting the values
P=|0×2+0×3+1×5+002+02+12|=5 Unit 
The distance of the point (2,3,5) from the xy-plane is 5 unit

The Plane Exercise 28.9 Question 8

Answer : The answer of the given question is 978 unit
Hint :
P=|ax1+by1+cz1+da2+b2+c2|
Given :
Points : A(3,3,3)
Plane : r(5i^+2j^7k^)+9=0, which in Cartesian form
Solution :
5x+2y7z+9=0 and point (3,3,3)
We know the distance of point (x1,y1,z1) from the plane
p:ax+by+cz+d=0 Is given by
P=|ax1+by1+cz1+da2+b2+c2|
Putting the values
P=|5×3+2×3+(7)×3+952+22+(7)2|=978 Units 
The distance of the point (3,3,3) from the plane,
r(5i^+2j^7k^)+9=0 is 978 Units 

The Plane Exercise 28.9 Question 9

Answer : The answer of the given question is λ=4
Hint :
P=|ax1+by1+cz1+da2+b2+c2|
Given : Points: (1,1,1) and xy+z+λ=0 be 5
Solution :
The distance of the point (1,1,1) from the origin
We know, distance of (x1,y1,z1) from the origin is x12+y12+z12
Putting values of x1,y1,z1=1
Required distance =3
Distance of the point (1,1,1) from plane xy+z+λ=0
We know, the distance of point (x1,y1,z1) from the plane π=ax+by+cz+d=0
Is given by
P=|ax1+by1+cz1+da2+b2+c2|
Putting necessary values,
P=|1×1+(1)×1+1×1+λ12+(1)2+12|P=|1+λ3|
According to the question
|1+λ3|×3=5|1+λ|=51+λ=5 Or 1+λ=5λ=4 Or λ=6
λ=4 [λ6 Because distance cannot be negative]

The Plane Exercise 28.9 Question 10

Answer : The answer of the given question is 37x+20y21z=61,67x20y+99z=121
Hint :
P=|ax1+by1+cz1+da2+b2+c2|
Solution : Let (x,y) be a point which is equidistant from the given plane. Then,
|3x4y+12z6|9+16+144=|4x+3z7|16+93x4y+12z613=±4x+3z75
15x20y+60z30=52x+39z91;15x20y+60z30=52x39z+9137x+20y21z=61;67x20y+99z=121
Therefore this is the required equation.

The Plane Exercise 28.9 Question 11

Answer : The answer of the given question is 29 Units
Hint :
P=|ax1+by1+cz1+da2+b2+c2|
Given :
3 Point (7,2,4) and the plane determine by the point
A(2,5,3),B(2,3,5)&(5,3,3)
Solution :
The equation of the plane passing through (x1,y1,z1),(x2,y2,z2)&(x3,y3,z3) is given by the following equation
|xx1yy1zz1x2x1y2y1z2z1x3x1y3y1z3z1|=0
According to questions
(x1,y1,z1)=(2,5,3)(x2,y2,z2)=(2,3,5)(x3,y3,z3)=(5,3,3)
Putting these values
|x2y5z(3)488320|=0
(x2)(16)+(y5)(24)+(z+3)(32)=02x+3y+4z7=0
Distance of 2x+3y+4z7=0 from (7,2,4)
We know, the distance of point (x1,y1,z1) from the plane
π:ax+by+cz+d=0 Is given by
P=|ax1+by1+cz1+da2+b2+c2|P=|2×7+3×2+4×4722+32+42|
P=29 Units

The Plane Exercise 28.9 Question 12

Answer : The answer of the given question is 1229 units
Hint :
P=|ax1+by1+cz1+da2+b2+c2|
Given : Plane makes intercept -6,3,4 respectively on the coordinate axes
Solution :
The equation of the plane which makes intercept a, b and c with the x, y and z axes respectively is
xa+yb+zc=1
Putting the values of a, b and c
Require equation of the plane
x6+y3+z4=12x+4y+3z=12
We know, the distance of the point (x1,y1,z1) from the plane
π:ax+by+cz+d=0 Is given by
P=|ax1+by1+cz1+da2+b2+c2|
Distance from the origin i.e. (0,0,0):|da2+b2+c2|
Required distance
=|12(2)2+42+32|=1229
The length of the perpendicular from the origin on the plane =1229 Units 

The Plane Exercise 28.9 Question 13

Answer : 22
Hint :
P=|ax1+by1+cz1+da2+b2+c2|
Given : We have to find the distance of the point (1,2,4) from the plane passing through the point (1,2,2)
Solution : Let us consider the equation of plane passing through the point (1,2,2) be
a(x1)+b(y2)+c(z2)=0 (1)
The direction ratios of the normal to the plane are a, b and c
The equation of the plane are
xy+2z=32x2y+z+12=0
Since the plane passing through the point (1,2,2) is perpendicular the given plane
Therefore,
ab+2c=02a2b+c=0
Now, eliminating a, b and c from (1), (2) and (3)
We get
|x1y2z2112221|=0(x1)(1+4)(y2)(14)+(z2)(2+2)=0
3(x1)+3(y2)+0=03x3+3y6=03x+3y9=0x+y3=0
Now using distance formula
The distance of the point (1,2,4) from the plane x+y3=0 is
=|12312+12+02|=|42|=22 Units 

The RD Sharma class 12th exercise 28.9 covers the chapter 'The Plane.' There are about 19 questions in this exercise that are extremely basic and simple and covers all the essential concepts that are mentioned below-

  • Intercept form of the equation

  • Distance of the point from the plane

  • Equation of plane passing through points

  • Points are equidistant from the plane

  • Equation of plane passing through three points

Listed below are a few reasons that gives a brief idea about why the RD Sharma class 12 solution of The plane exercise 28.9 is the best solution for mathematics:-

  • The RD Sharma class 12th exercise 28.9 is available online on the Career360 website for download, thus you don't have to visit any stores to buy the solution.

  • You just need to have a good internet connection and a digital device to download the RD Sharma class 12 solution chapter 28 exercise 28.9 which is available free of cost on the Career360 website.

  • The experts of mathematics prepare the questions of the RD Sharma class 12 chapter 28 exercise 28.9 which makes the questions trustworthy and helpful tips can also be referred in the book for an alternate way to solve the questions easily.

  • It has been found that most of the questions that are asked in the 12th board exams are similar to the ones that are provided in the RD Sharma solution, therefore having a thorough practice of the solution can help you score high in the exams.

  • The exercises given in the RD Sharma class 12th exercise 28.9 are divided into two levels so that the students can distinguish easily between the low level and high level questions and practice accordingly.

  • The RD Sharma solutions are the best study material for any students who have the ambition to score high marks in the board exams and therefore teachers of all the CBSE schools recommend making use of this solution to practice rigorously.

NEET Highest Scoring Chapters & Topics
This ebook serves as a valuable study guide for NEET exams, specifically designed to assist students in light of recent changes and the removal of certain topics from the NEET exam.
Download E-book

RD Sharma Chapter-wise Solutions

Frequently Asked Questions (FAQs)

1. Who can use this material?

CBSE students who want to gain in depth knowledge on the subject can use this material.

2. How can I use this material?

RD Sharma class 12 chapter 28 material can act as a guide for students for their preparation. This will help them save time and study efficiently for their exams.

3. Can I refer to this material for my homework?

RD Sharma class 12 chapter 28 material is comprehensive and contains step-by-step solutions. This can help students better understand the concepts and finish their homework easily. 

4. Is this material updated to the latest version?

Yes, RD Sharma class 12 chapter 28 material is updated to the latest version and is available for free on Career360’s website. 

5. From where can I access this material?

Career360 provides RD Sharma class 12 chapter 28 material for free on their website. Students can use it through any device with an internet connection.

Articles

Upcoming School Exams

Application Date:24 March,2025 - 23 April,2025

Admit Card Date:25 March,2025 - 21 April,2025

Admit Card Date:25 March,2025 - 17 April,2025

View All School Exams
Back to top