Question

What is the 4th term in a geometric sequence for which a1=10 and r=.5

Answer 1

First term a1=10 & r=0.5 & n=4

The formula to find the term =a(n) = a(1)*(r)^(n-1)

a(4th)=10*(0.5)^3 =1.25


proof:


a1=10

a2=10*0.5=5

a3= 5*0.5 = 2.5

a4= 2.5*0.5=1.25