Q. Find the 99th term of the arithmetic sequence −4,7,18,…Answer:
Identify First Term and Common Difference: To find the 99th term of an arithmetic sequence, we need to know the first term (a1) and the common difference (d). The first term is given as −4.
Calculate Common Difference: The common difference d can be found by subtracting the first term from the second term. So, d=7−(−4)=7+4=11.
Apply Formula for nth Term: Now that we have the common difference, we can use the formula for the nth term of an arithmetic sequence, which is an=a1+(n−1)d. We want to find the 99th term, so n=99.
Substitute Values and Calculate: Substitute the known values into the formula to find a99. a99=−4+(99−1)×11=−4+98×11.
Perform Multiplication: Perform the multiplication: 98×11=1078.
Perform Addition: Now, perform the addition: a99=−4+1078=1074.
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