Question

Which term will be the first negative term in the arithmetic progression 133, 125,
117...?​

Answer 1

Answer:-

n = 18

Given :-

133 , 125 , 117 ......

To find :-

The first negative term.

Solution:-

Let a be the first term and d be the common Difference .

a = 133

d = 125 - 133

d = - 8

The first term should be in negative therefore

$a_n <0$

Now,

→$a + (n-1)d <0$

→$133 + (n-1)-8 <0$

→$133-8n +8 <0$

→$141 -8n <0$

→$141 <8n$

→$\dfrac{141}{8}< n$

→$17.6< n$

→ $n = 18$

hence, the first negative term in AP will be 18 th term .