मराठी

Find the Geometric Means of the Following Pairs of Number: A3b and Ab3 - Mathematics

Advertisements
Advertisements

प्रश्न

Find the geometric means of the following pairs of number:

a3b and ab3

Advertisements

उत्तर

\[\text {  Let the G . M . between }a^3 \text { b and a } b^3 \text { be G } . \]

\[\text { Then,} a^3 \text { b, G and } a b^3 \text { are in G . P } . \]

\[ \therefore G^2 = a^3 b \times a b^3 \]

\[ \Rightarrow G^2 = a^4 b^4 \]

\[ \Rightarrow G = \sqrt{a^4 b^4}\]

\[ \Rightarrow G = a^2 b^2\]

shaalaa.com
  या प्रश्नात किंवा उत्तरात काही त्रुटी आहे का?
पाठ 20: Geometric Progression - Exercise 20.6 [पृष्ठ ५५]

APPEARS IN

आरडी शर्मा Mathematics [English] Class 11
पाठ 20 Geometric Progression
Exercise 20.6 | Q 4.2 | पृष्ठ ५५

व्हिडिओ ट्यूटोरियलVIEW ALL [1]

संबंधित प्रश्‍न

Which term of the following sequence: 

`2, 2sqrt2, 4,.... is 128`


If the 4th, 10th and 16th terms of a G.P. are x, y and z, respectively. Prove that x, y, z are in G.P.


If the pth, qth and rth terms of a G.P. are a, b and c, respectively. Prove that `a^(q - r) b^(r-p) c^(p-q) = 1`.


The first term of a G.P. is 1. The sum of the third term and fifth term is 90. Find the common ratio of G.P.


Show that the sequence <an>, defined by an = \[\frac{2}{3^n}\], n ϵ N is a G.P.


Find:

the 10th term of the G.P.

\[- \frac{3}{4}, \frac{1}{2}, - \frac{1}{3}, \frac{2}{9}, . . .\]

 


The seventh term of a G.P. is 8 times the fourth term and 5th term is 48. Find the G.P.


The sum of three numbers in G.P. is 14. If the first two terms are each increased by 1 and the third term decreased by 1, the resulting numbers are in A.P. Find the numbers.


Find the sum of the following geometric progression:

1, 3, 9, 27, ... to 8 terms;


Find the sum of the following geometric series:

\[\sqrt{2} + \frac{1}{\sqrt{2}} + \frac{1}{2\sqrt{2}} + . . .\text { to 8  terms };\]


Find the sum of the following geometric series:

x3, x5, x7, ... to n terms


Find the sum of the following series:

7 + 77 + 777 + ... to n terms;


The sum of n terms of the G.P. 3, 6, 12, ... is 381. Find the value of n.


If S1, S2, S3 be respectively the sums of n, 2n, 3n terms of a G.P., then prove that \[S_1^2 + S_2^2\] = S1 (S2 + S3).


Show that the ratio of the sum of first n terms of a G.P. to the sum of terms from (n + 1)th to (2n)th term is \[\frac{1}{r^n}\].


Find the sum of the following serie to infinity:

8 +  \[4\sqrt{2}\] + 4 + ... ∞


Find the sum of the following series to infinity:

10 − 9 + 8.1 − 7.29 + ... ∞


Prove that: (21/4 . 41/8 . 81/16. 161/32 ... ∞) = 2.


Three numbers are in A.P. and their sum is 15. If 1, 3, 9 be added to them respectively, they form a G.P. Find the numbers.


If \[\frac{1}{a + b}, \frac{1}{2b}, \frac{1}{b + c}\] are three consecutive terms of an A.P., prove that a, b, c are the three consecutive terms of a G.P.


If a, b, c are in A.P. and a, b, d are in G.P., show that a, (a − b), (d − c) are in G.P.


If a, b, c are three distinct real numbers in G.P. and a + b + c = xb, then prove that either x< −1 or x > 3.


Find the geometric means of the following pairs of number:

2 and 8


The sum of an infinite G.P. is 4 and the sum of the cubes of its terms is 92. The common ratio of the original G.P. is 


Given that x > 0, the sum \[\sum^\infty_{n = 1} \left( \frac{x}{x + 1} \right)^{n - 1}\] equals 


Check whether the following sequence is G.P. If so, write tn.

2, 6, 18, 54, …


For a G.P. if a = 2, r = 3, Sn = 242 find n


For a G.P. If t4 = 16, t9 = 512, find S10


Find: `sum_("r" = 1)^10(3 xx 2^"r")`


Find: `sum_("r" = 1)^10 5 xx 3^"r"`


If the first term of the G.P. is 16 and its sum to infinity is `96/17` find the common ratio.


Select the correct answer from the given alternative.

The common ratio for the G.P. 0.12, 0.24, 0.48, is –


The sum of 3 terms of a G.P. is `21/4` and their product is 1 then the common ratio is ______.


Answer the following:

For a sequence , if tn = `(5^("n" - 2))/(7^("n" - 3))`, verify whether the sequence is a G.P. If it is a G.P., find its first term and the common ratio.


Answer the following:

Find five numbers in G.P. such that their product is 243 and sum of second and fourth number is 10.


Answer the following:

If pth, qth and rth terms of a G.P. are x, y, z respectively. Find the value of xq–r .yr–p .zp–q


At the end of each year the value of a certain machine has depreciated by 20% of its value at the beginning of that year. If its initial value was Rs 1250, find the value at the end of 5 years.


If pth, qth, and rth terms of an A.P. and G.P. are both a, b and c respectively, show that ab–c . bc – a . ca – b = 1


For a, b, c to be in G.P. the value of `(a - b)/(b - c)` is equal to ______.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×