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

2 Answers
Dec 11, 2017

Answer:

#a_n=3n-2#

Explanation:

a generalised AP is given by

#a,a+d,a+2d,....a+(n-1)d#

in this case we have

#a_1=1,d=3#

so

#a_n=1+3(n-1)=1+3n-3#

#a_n=3n-2#

Dec 11, 2017

Answer:

#a_n=3n-2#

Explanation:

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

#•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#