Terms of geometric sequence are found by the formula T n = ar n - 1. If a = 3 and r = 2, find the first 4 terms of the sequence.

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 3, 6, 12, 24

Step-by-step explanation:

It helps if the formula is properly written.

 Tn = a·r^(n-1)

Fill in the given values for a, r, and use n = 1 to 4.

 T1 = 3·2^(1-1) = 3

 T2 = 3·2^(2-1) = 6

 T3 = 3·2^(3 -1) = 12

 T4 = 3·2^(4 -1) = 24

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Additional comment

The value a=3 tells you the first term is 3. The value r=2 tells you each term is 2 times the previous one. Knowing this, you can write down the sequence based on your knowledge of multiplication tables (×2). You can use the formula as we did above, but it isn't necessary.

 3, 6, 12, 24, ...