Look at the graph of the arithmetic sequence Hanh If an is a

Look at the graph of the arithmetic sequence Hanh. If an) is a finite sequence whose last term is 74, how many terms does (an) contain? The arithmetic sequence Hanh contains terms. Hanh

Solution

From graph arithmetic sequence is going on in following manner:-

-1, 2, 5, 8, 11, ...........

as we know that in an AP n^th term that is a_n=a+(n-1)d

where a is the first term and d is the common difference

in our case first term that is a = -1, d=3, and last term that is a_n=74

so from above formulae

74= -1 + (n-1)3

75=3(n-1)

n=26

so number of terms =26