Write a formula for the nth term of the given geometric sequence. 3, -6, 12, ...

Question

Quizplus · Accepted Answer

The common ratio between each term is -2, as each term is multiplied by -2 to get the next term. 
So, the formula for the nth term of a geometric sequence with first term a and common ratio r is: 
an = ar^(n-1)

Substituting a=3 and r=-2: 
an = 3*(-2)^(n-1)

Therefore, the correct formula for the nth term of the sequence 3, -6, 12, ... is: 
a_n = 3*(-2)^(n-1)

Option C matches this formula.

Write a Formula for the Nth Term of the Given