Date:Day 14. F-IF.1.3Find the first five terms of the recursive sequence defined by the function below. f(n)=2f(n−1)+3n, where f(1)=−25. F-LE.1.2The third term in an arithmetic sequence is 10 and the fifth term is 26 . If the first term is a1, which is an equation for the nth term of this sequence?
Q. Date:Day 14. F-IF.1.3Find the first five terms of the recursive sequence defined by the function below. f(n)=2f(n−1)+3n, where f(1)=−25. F-LE.1.2The third term in an arithmetic sequence is 10 and the fifth term is 26 . If the first term is a1, which is an equation for the nth term of this sequence?
Calculate f(5): Finally, we find f(5).f(5)=2f(5−1)+3×5f(5)=2f(4)+15f(5)=2×38+15f(5)=76+15f(5)=91
Write nth term: Now we can write the nth term of the arithmetic sequence.The nth term an=a1+(n−1)dSince we know d=8, we substitute it into the equation.an=a1+(n−1)×8
Find a1: To find a1, we use the third term which is 10.10=a1+(3−1)⋅810=a1+2⋅810=a1+16a1=10−16a1=−6
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