Q. Find an explicit formula for the arithmetic sequence−11,−3,5,13,…Note: the first term should be b(1).b(n)=□
Determine First Term: To find an explicit formula for an arithmetic sequence, we need to determine the first term (b(1)) and the common difference (d). The first term is given as −11.
Calculate Common Difference: Next, we calculate the common difference d by subtracting the first term from the second term: d=−3−(−11)=−3+11=8.
Write Explicit Formula: Now that we have the first term b(1)=−11 and the common difference d=8, we can write the explicit formula for the nth term of the arithmetic sequence as b(n)=b(1)+(n−1)d.
Substitute Values: Substitute the values of b(1) and d into the formula: b(n)=−11+(n−1)8.
Simplify Formula: Simplify the formula to get the final explicit formula: b(n)=−11+8n−8.
Combine Like Terms: Combine like terms to get the simplified explicit formula: b(n)=8n−19.