Q. Find the 11th term of the geometric sequence shown below.−3x2,9x6,−27x10,…Answer:
Identify terms and ratio: Identify the first term a1 and the common ratio r of the geometric sequence.The first term a1 is given as −3x2.To find the common ratio r, we divide the second term by the first term.r=−3x29x6=−3x6−2=−3x4
Find 11th term formula: Use the formula for the nth term of a geometric sequence to find the 11th term.The nth term an of a geometric sequence is given by an=a1⋅r(n−1).We want to find the 11th term, so n=11.a11=a1⋅r(11−1)=a1⋅r10
Substitute and calculate: Substitute the values of a1 and r into the formula to calculate the 11th term.a11=(−3x2)⋅(−3x4)10a11=(−3x2)⋅(−3)10⋅(x4)10a11=(−3x2)⋅(59049)⋅(x40)
Simplify for 11th term: Simplify the expression to find the 11th term.a11=(−3)×59049×x(2+40)a11=(−3)×59049×x42a11=−177147×x42
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