# How do you find the formula for #a_n# for the arithmetic sequence #a_1=1, d=3#?

##### 2 Answers

Dec 11, 2017

#### Explanation:

a generalised AP is given by

in this case we have

so

Dec 11, 2017

#### Explanation:

#"the nth term of an arithmetic sequence is "#

#â€¢color(white)(x)a_n=a+(n-1)d#

#"where a is the first term and d the common difference"#

#"here "a=1" and "d=3#

#rArra_n=1+3(n-1)=3n-2#