Question

Check whether the list of numbers is an AP or not? -10, -6, -2, 2, ……………

Answer 1

Answer:

According to the question,

a1 = – 10

a2 = – 6

a3 = – 2

a4 = 2

a2 – a1 = 4

a3 – a2 = 4

a4 – a3 = 4

a2 – a1 = a3 – a2 = a4 – a3 = 4

Therefore, it’s an A.P with d = 4

Answer 2

Answer:

This list of numbers is an AP.

Step-by-step explanation:

A list of numbers is called an AP if the next term is added by a constant which is called d. We need to find if d in this list exists or not. If it exists, then  it is an AP. We know that,

d=$a_{n}-a_{n-1}$

Given, $a_{1}$=-10, $a_{2}$=-6, $a_{3}$=-2

We find d using first term and second term, then using second term and third term. If the results are the same, then this list is an AP.

d=$a_{2}$-$a_{1}$

=-6-(-10)

=-6+10=4

d=$a_{3}$-$a_{2}$

=-2-(-6)

=-2+6=4

We see that $a_{2}-a_{1} = a_{3}-a_{2} = 4$

Therefore, this list of numbers is an AP.