Question

Which term of the A.P. 41,38,35,.... is the first negative term? Find the term also.

Answer 1

we can solve it with hit and trial method .

let us consider the negative number to be -1

so by using the formula = a+(n-1)d where a=41 , d= -3

=> 41+(n-1)-3 = -1

=>41 -3n +3 = -1

=>44-3n = -1

=>-3n = -44-1

=>n= -45/-3

therefore n= 15 , so we can say that the first negative tern of the given ap is the fifteenth term which is -1 .

we can verify this by replacing the value of n in the formula a+(n-1)d .