Given the nth term for this arithmetic sequence, how to find the common difference and the first four terms too? #a_n# = 3n - 2

1 Answer

The first four terms are
#a_1=1#
#a_2=4#
#a_3=7#
#a_4=10#

Common difference is
#d=3#

Explanation:

#a_n=3n-2#
#n=1#

#a_1=3x1-2=3-2=1#
#n=2#
#a_2=3x2-2=6-2=4#
#n=3#
#a_3=3x3-2=9-2=7#
#n=4#
#a_4=3x4-2=12-2=10#

The first four terms are
#a_1=1#
#a_2=4#
#a_3=7#
#a_4=10#
Common difference is
#a_2-a_1=4-1=3#
#a_3-a_2=7-4=3#
#a_4-a_3=10-7=3#

#d=3#