Arithmetic Progression
It is a sequence of numbers wherein each term differs by its preceding term by a constant ,is called Arithmetic progression(AP)and the constant is called common difference.(cd)
Common difference is given by 2nd term -1st term= 3rd term- 2nd term= 4th term -3rd term=5th term-4th term and so on.
For example - The sequence of numbers 1 ,4 , 7, 10 , 13, ............ are in AP.
Whose first term is 1 and Common difference = 2nd term - first term=4-1=3
Hence nth term is given by Tn= a+(n-1)*d = 1+(n-1)*3 = 3n-2
The sequence of numbers -5, -3 , -1 ,1 ,......are in AP.
Ist term = -5 and Common difference= -3-(-5)= +2
Hence nth term is given by Tn= a+(n-1)*d = -5+(n-1)*2 = 2n-7.
