Question

If u1=-1, u2=-5 and ur=a+br, find a, b and u6

Answer 1

The given sequence can be represented as u1, u2, u3, u4, u5, u6 where u1 = -1 and u2 = -5.

Since the sequence is in linear form, we can write:

u1 = a + b(1)

u2 = a + b(2)

Solving these two equations, we get:

a = -3, and b = -2

Using the same formula, we can find the value of u6:

u6 = a + b(6)

u6 = -3 - 2(6)

u6 = -15

Therefore, a = -3, b = -2, and u6 = -15