Question

Find which is the first negative term of sequence 18,33÷2,15,27÷2....

Answer 1

Answer:3/4

Step-by-step explanation:a=20 and d=77/4-20=-3/4

to find the first negative term of the AP first assume that

Tn=0

a+(n-1)d=0

20+(n-1)(-3/4)

20+3/4-3/4n=0

-3/4n=-83/4

n=83/3

n=27.66

it means that 28th term is the first negative term

now T28=a+27d

20+27(-3/4)

20+(-81/4)

(80-81)/4

therefore -1/4 is the first negative term of the given AP