Question

how to find common difference​

Answer 1

The formula is a2-a1

which means you have to subtract first term from second.

Example:

AP:2, 4,6,8....

Common difference =4-2=2

Answer 2

Let any A.P. such as

2, 5, 8, 11, 14, 17, ..........

then, a is it's first term

Let, first term, second term, third term, .........

first term = t1 = 2

second term = t2 = 5

third term = t3 = 8

...........

...........

.............

then after this to get common difference, subtract the term from its next term.

such as,

t2 - t1 = 5-2 = 3

hence, the common difference = D = 3