One of the most important question of important chapter for board examination
Find the nth term and 12th term of the list numbers:5,2,-1,-4,…..
ML Publication, Exercise 9, arithmetic progression
Find the nth term and 12th term of the list numbers:5,2,-1,-4,…..
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From the question,
The first term a=5
Then, difference d=2−5=−3
−1−3=−3−4−(−1)=−4+1=−3​
Therefore, common difference d=−3 From the formula,
an​=a+(n−1)d
Tn​= So, T12​​a+(n−1)d=5+(n−1)(−3)=5−3n+3=8−3n=a+(12−1)d=5+(12−1)(−3)=5+(11)−3=5−33=−28​