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8 th term will be 0
equate the general Formula by 0
equate the general Formula by 0
snehavinod34:
In this question, what should we find.. The nth term or the an?
nth term and an is equal
an = nth term = a + (n-1)d =0
put the values and u will get 8th term as answer
So, if there is a ques. Which says that check whether -10 is a term in a AP or not. So, is -10 n or an?
an
How can v know that?
Answered by
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There is formula for nth term.
= 
+ (n - 1)d
where d is common difference of the AP
-81 = 21 + (n - 1)(-3)
⇒ -102/-3 = n - 1
⇒ 34 = n - 1
⇒ n = 35
35th term will be -81
+ (n - 1)d = 0
⇒ 21 + (n - 1)(-3) = 0
⇒ n - 1 = 7
⇒ n =8
8th term will be 0.
where d is common difference of the AP
-81 = 21 + (n - 1)(-3)
⇒ -102/-3 = n - 1
⇒ 34 = n - 1
⇒ n = 35
35th term will be -81
⇒ 21 + (n - 1)(-3) = 0
⇒ n - 1 = 7
⇒ n =8
8th term will be 0.
So, what will be the question if v have to find an?
Here, an is given as -81 and in second question, an is given as 0. So put it the given formula, and you will get n.
Saying n means general where n can be any natural number ( 1,2,3,.....) and an means the value of that term, like a1 ( 1st term) in this AP is 21, a2(2nd term) in this AP is 18. Since the AP is decreasing, common difference is negative.
But, how can v know which is Asked in the ques. An or n?
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