Q. Find the 87 th term of the arithmetic sequence −26,−11,4,…Answer:
Question Prompt: Question prompt: What is the 87th term of the arithmetic sequence −26,−11,4,…?
Identify Common Difference: Identify the common difference d of the arithmetic sequence by subtracting the first term from the second term.d=−11−(−26)d=−11+26d=15
Use Formula for nth Term: Use the formula for the nth term of an arithmetic sequence: an=a1+(n−1)d, where an is the nth term, a1 is the first term, and d is the common difference.We need to find the 87th term (a87), so n=87, a1=−26, and d=15.
Substitute Values: Substitute the values into the formula to find the 87th term.a87=−26+(87−1)×15a87=−26+(86×15)
Calculate Inside Parentheses: Calculate the value inside the parentheses first. 86×15=1290
Substitute Calculated Value: Now, substitute the calculated value back into the equation. a87=−26+1290
Perform Addition: Perform the addition to find the 87th term.a87=1264
More problems from Solve exponential equations using logarithms