Question

If Tn = 2n - 1 then find t5

Answer 1

Tn = 2n -1
Therefore,
T5 = 2×5-1= 10-1=9

Answer 2

Tn = 2n - 1
=> a +(n-1)d = 2n - 2 + 1
=> a + (n-1)d = 1 + 2(n-1)

Comparing both sides, we get
a= 1
d = 2

T5 = a + 4d
= 1 + 8
= 9