Question

The nth term of a sequence n3+1 is 28, then find n

Answer 1

Step-by-step explanation:

Solution. .AP is 3n+1 for n=1. a =3×1+1=4=a1. similarly for n=2. a+d=3×2+1=7=a2.

d =a2-a1=7-4=3. an=28=a+(n-1)d. 4+( n-1)3=28. 3(n-1)=28-4. 3(n-1)=24. n-1=24 /3. n-1=8 n=8+1. Therefore. n=9 (answer). HOPE IT HELP U!!!!