Class 10

Math

All topics

Sequences and Series

Check whether $−150$ is a term of the AP : $11,8,5,2.....$

$a=11$ and $d=8−11=−3$

$T_{n}=−150$

$a+(n−1)d=−150$

$⇒11+(n−1)(−3)=−150$

$⇒11−3n+3=−150$

$⇒14−3n=−150$

$⇒3n=−164$

$∴n=−3164 =−54.66$

$n$ is not an integer.

So, it is not in A.P.