Q. Find the 13th term of the geometric sequence 6,18,54,…Answer:
Identify first term: To find the 13th term of a geometric sequence, we need to use the formula for the nth term of a geometric sequence, which is an=a1⋅r(n−1), where a1 is the first term, r is the common ratio, and n is the term number.
Find common ratio: First, we identify the first term a1 of the sequence, which is 6.
Calculate 13th term: Next, we need to find the common ratio r. We can do this by dividing the second term by the first term, or the third term by the second term. Let's use the second term divided by the first term: r=618=3.
Calculate power of ratio: Now that we have the first term and the common ratio, we can find the 13th term a13 using the formula: a13=a1×r(13−1)=6×312.
Multiply to find term: We calculate 312. 312=3×3×3×3×3×3×3×3×3×3×3×3=531,441.
Multiply to find term: We calculate 312. 312=3×3×3×3×3×3×3×3×3×3×3×3=531,441.Finally, we multiply the first term by 312 to find the 13th term: a13=6×531,441=3,188,646.