The 6th term of an ap is zero prove that the 21th term is triple it and 11th term
Answers
Answered by
1
The first term is a and the common difference is d.
The nth term is a + (n-1)d.
t₆ = a + (6-1)d = a + 5d = 0
5d = -a
d = -a/5
t₁₁ = a + (11-1)d
= a + 10d
= -a
t₂₁ = a + (21-1)d
= a + 20d
= -3a
Therefore, t₂₁ = 3t₁₁
The nth term is a + (n-1)d.
t₆ = a + (6-1)d = a + 5d = 0
5d = -a
d = -a/5
t₁₁ = a + (11-1)d
= a + 10d
= -a
t₂₁ = a + (21-1)d
= a + 20d
= -3a
Therefore, t₂₁ = 3t₁₁
Similar questions