Find the product of 11 terms in G.P whose 6th term is 5
@ganeshie8
Middle term is 5 this means
wow ! yes we can use symmetry
yesss
\[\large a_1 a_2 a_3 a_4 \cdots a_{11}\]
A_1 * A_11 = A _2 * A _10 Like this right
that looks perfect !!
5^11
!!!
middle term = geometric mean
\(\large a_6 = \sqrt{a_1 \times a_{11}} = \sqrt{a_2 \times a_{10}} = \cdots \)
5^11 is correct !
There is a formula for the product of n terms in G.P i saw it on wikipedia
But we can't really use it here
\(\large a_1, a_1r, a_1r^2, \cdots \) product = \(\large a_1 \times a_1r \times a_1r^2 \cdots \)
if there are n terms : product = \(\large a_1^n r^{0 + 1 + 2 + \cdots n-1}\)
product = \(\large a_1^n r^{\frac{n(n-1)}{2}}\)
yes!
nice :)
Actually there is so much work done in this chapter especially by Euclid I felt that doing some more 15 pages i would attain a mastery at this concept , but i was stumped by reading wikipedia
One can study a math concept till his death and still he won't learn everything
true ! cuz its so much fun that one doesn't feel like giving it up - so one pursues it till one's death xD
hahahhah
Join our real-time social learning platform and learn together with your friends!