SEQUENCES AND SERIES — MATHS STD 11 Science — Question
Gujarat BoardEnglish MediumSTD 11 ScienceMATHSSEQUENCES AND SERIES1 Mark
Question
Insert three numbers between 1 and 256 so that the resulting sequence is a G.P.
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Answer
Suppose $G_1, G_2, G_3$ be three numbers between 1 and 256 such that $1, G_1, G_2, G_3, 256$ is a G.P.
Thus, $256=r^4$ giving $r= \pm 4$ (Taking real roots only)
For $r=4$, we have $G_1=a r=4, G_2=a r^2=16, G_3=a r^3=64$
Similarly, for $r=-4$, numbers are $-4,16$ and -64
Therefore, we can insert $4,16,64$ between 1 and 256 so that the resulting sequences are in G.P.
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