1 2 3 4 5 6 7 8 A 8 B 8 C 8 D 8 E 9 A 9 B 9 C 10 A 10 B 10 C 11 A 11 B 11 C 11 D 12 13 14 15 16 17 18 19 20 21 22 23

RD Sharma - Mathematics

20. Geometric Progressions

1. Sets
2. Relations
3. Functions
4. Measurement of Angles
5. Trigonometric Functions
6. Graphs of Trigonometric Functions
7. Values of Trigonometric Functions at Sum of Difference of Angles
8. Transformation Formulae
9. Values of Trigonometric Functions at Multiples and Submultiple of an Angles
10. Sine and Cosine Formulae and their Applications
11. Trigonometric Equations
12. Mathematical Induction
13. Complex Numbers
14. Quadratic Equations
15. Linear Inequations
16. Permutations
17. Combinations
18. Binomial Theorem
19. Arithmetic Progressions
20. Geometric Progressions
21. Some Special Series
22. Brief Review of Cartesian System of Rectangular Co-ordinates
23. The Straight Lines
24. The Circle
25. Parabola
26. Ellipse
27. Hyperbola
28. Introduction to 3-D Coordinate Geometry
29. Limits
30. Derivatives
31. Mathematical Reasoning
32. Statistics
33. Probability

Exercise 20.1

1 2 3 A 3 B 3 C 3 D 3 E 3 F 4 5 6 A 6 B 6 C 6 D 7 8 9 10 11 12 13 14 15 16 17

Exercise 20.2

1 2 3 4 5 6 7 8 9

Exercise 20.3

1 A 1 B 1 C 1 D 1 E 2 A 2 B 2 C 2 D 2 E 2 F 2 G 2 H 2 I 3 A 3 B 3 C 4 A 4 B 4 C 4 D 4 E 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22

Exercise 20.4

1 A 1 B 1 C 1 D 1 E 2 3 4 5 6 7 8 A 8 B 8 C 8 D 9 10 11 12 13

Exercise 20.5

1 2 3 4 5 6 7 8 A 8 B 8 C 8 D 8 E 9 A 9 B 9 C 10 A 10 B 10 C 11 A 11 B 11 C 11 D 12 13 14 15 16 17 18 19 20 21 22 23

Exercise 20.6

1 2 3 4 5 6 7 8 9 10 11 12 13

Very Short Answer

1 2 3 4 5 6 7 8 9 10

MCQ

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

Q. 215.0( 3 Votes )

If a, b, c are in

Class 11th RD Sharma - Mathematics 20. Geometric Progressions

Answer :

a, b, c are in AP

So, 2b = a + c …(1)

b, c, d are in GP

So, b² = ad …(2)

Multiply first equation with a and subtract it from 2nd.

b² – 2ab = ad – ac – a²

⇒ a² + b² – 2ab = a(d – c)

Hence a, (a – b), (d – c) are in G.P.

Rate this question :

How useful is this solution?

We strive to provide quality solutions. Please rate us to serve you better.

PREVIOUSIf a, b, c are in NEXTIf a, b, c are th

Try our Mini CourseMaster Important Topics in 7 DaysLearn from IITians, NITians, Doctors & Academic Experts

Dedicated counsellor for each student

24X7 Doubt Resolution

Daily Report Card

Detailed Performance Evaluation

caricature

view all courses

RELATED QUESTIONS :

If AM and GM of tRD Sharma - Mathematics

If AM and GM of rRD Sharma - Mathematics

Write the quadratRS Aggarwal - Mathematics

<span lang="EN-USRD Sharma - Mathematics

Find the two numbRD Sharma - Mathematics

Insert 5 geometriRD Sharma - Mathematics

If a, b, c are inRD Sharma - Mathematics

Prove that the prRD Sharma - Mathematics

Construct a quadrRD Sharma - Mathematics

If a, b, c are inRD Sharma - Mathematics