Use the formula for the general term (the nth term) of a geometri...

Question

Use the formula for the general term (the nth term) of a geometric sequence to find the indicated term of the sequence. Find a(sub 7) when a(sub 1) = 2, r = 3

Accepted Answer

Welcome back. I'm so glad you're here. We've got a geometric sequence with some givens. We know that a sub one equals two that are equal six. And now we're trying to find a sub five ace of five. That means we're trying to find the fifth terms value. So we know that a sub five Gives us the 5th terms values or n equals five. And we know from previous lessons that we've got a formula for finding a sub N. Finding any terms value. And our formula is a sub one or the value of the first term times R times the ratio race to the n minus one. We know all of these so we can start filling them in. A sub one is two Times are which is six raised to the end which is -1. Simplifying. We've got two times six raised to the five minus one. Is four Or two times 6 to the 4th is 1296. two times 1296 is 2592. We look at our answer choices and that matches with answer choice B Well done, we'll catch you on the next one.

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