Q. Find the common ratio of the geometric sequence {an}n=1∞ given that:a2=−41a6=−2/312
Identify first term: Identify the first term (a1) of the geometric sequence.Given that a1=−41, we can use this value to find the common ratio.
Identify sixth term: Identify the sixth term a6 of the geometric sequence.Given that a6=−3212, we need to simplify this fraction to find the actual value of a6.a6=−12×(23)=−18
Find common ratio: Use the formula for the nth term of a geometric sequence to find the common ratio r. The nth term of a geometric sequence is given by an=a1⋅r(n−1). We can use the first term a1 and the sixth term a6 to find the common ratio r. a6=a1⋅r(6−1)−18=(−41)⋅r5
Solve for ratio: Solve for the common ratio r. To isolate r, we divide both sides of the equation by a1. r5=−18/(−1/4)r5=18×(4/1)r5=72 Now, take the fifth root of both sides to solve for r. r=721/5
Calculate value of r: Calculate the fifth root of 72 to find the value of r.r≈2.6390158215457884 (using a calculator)