Question

F(1)=3;f(n)=f(n-1)+7 Write the first four terms of the arithmetic sequence

Answer 1

1- f(1) =3

2- f(2)= f(2-1)+7
=f(1) +7
=3+7
f(2) =10

3- f(3)= f(3-1)+7
=f(2)+7
=10+7
f(3)=17

4- f(4)= f(4-1)+7
=f(3)+7
=17+7
f(4)=24

Answer 2

$\bf \begin{array}{lll} term&f(n)\qquad &f(n-1)+7\\ \cline{1-3}\\ 1&f(1)&3\\ 2&f(2)&f(2-1)+7\\ &&f(1)+7\\ &&3+7\\ &&10\\ 3&f(3)&f(3-1)+7\\ &&f(2)+7\\ &&10+7\\ &&17\\ 4&f(4)&f(4-1)+7\\ &&f(3)+7\\ &&17+7\\ &&24 \end{array}$