Write an expression to describe the sequence below. Use n to represent the position of a term in the sequence, where n=1 for the first term.77,154,231,308,…an=_____
Q. Write an expression to describe the sequence below. Use n to represent the position of a term in the sequence, where n=1 for the first term.77,154,231,308,…an=_____
Sequence Type: We have: 77,154,231,308,…Is the given sequence geometric or arithmetic? To determine this, we can look at the differences or ratios between terms.
Calculate Differences:77,154,231,308,…Calculate the difference between consecutive terms to see if it is constant.Difference between second and first term: 154−77=77Difference between third and second term: 231−154=77Difference between fourth and third term: 308−231=77Since the differences are constant, the sequence is arithmetic.
Find a1 and d: Determine the values of a1 and d of the sequence.The first term, a1=77Common difference, d=77 (as calculated in the previous step)
Arithmetic Sequence Formula: We have the formula for the nth term of an arithmetic sequence: an=a1+(n−1)da1=77d=77 Write an expression to describe 77,154,231,308,…an=77+(n−1)×77
Simplify Expression: Simplify the expression:an=77+77n−77an=77nThis is the expression that describes the sequence.
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