Q. Find the 12th term of the geometric sequence 5,25,125,…Answer:
Identify type of sequence: Identify the type of sequence.The given sequence is geometric because each term after the first is found by multiplying the previous term by a constant called the common ratio.
Determine common ratio: Determine the common ratio r of the sequence.To find the common ratio, divide the second term by the first term.525=5Common Ratio r: 5
Use formula for nth term: Use the formula for the nth term of a geometric sequence.The nth term an of a geometric sequence can be found using the formula an=a1×r(n−1), where a1 is the first term and r is the common ratio.
Calculate 12th term: Calculate the 12th term using the formula.First term a1=5Common Ratio r=5n = 12a12=5×512−1=5×511
Perform exponentiation and multiplication: Perform the exponentiation and multiplication to find the 12th term.a12=5×511=5×48828125a12=244140625