The required sum = 2 x 128 + 4 x 32 + 8 x 8 + 16 x 2 + 32 x \( \dfrac{1}{2} \)
= 64[4 + 2 + 1 + \( \dfrac{1}{2} \)+ \( \dfrac{1}{2^2} \)]
Now, it’s seen that
4, 2, 1, \( \dfrac{1}{2} \), \( \dfrac{1}{2^2} \) is a G.P.
With first term, a = 4
Common ratio, r =\( \dfrac{1}{2} \)
We know,
\( s_n=\dfrac{a(1-r^n)}{1-r}\)
= \(8( \dfrac{32-1}{32})=\dfrac{31}{4}\)
Answered by Abhisek | 1 year agoConstruct a quadratic in x such that A.M. of its roots is A and G.M. is G.
Find the geometric means of the following pairs of numbers:
(i) 2 and 8
(ii) a3b and ab3
(iii) –8 and –2
Insert 5 geometric means between \( \dfrac{32}{9}\) and \( \dfrac{81}{2}\).