Answer:
f(10) = 38
Explanation:
Notice that this sequence is given in recurrent form, so you need to know the previous term in order to calculate the following one. Then let's get into all the 10 terms needed:
f(1) = 2
f(2) = 2 + 4 = 6
f(3) = 6 + 4 = 10
f(4) = 10 + 4 = 14
f(5) = 14 + 4 = 18
f(6) = 18 + 4 = 22
f(7) = 22 + 4 = 26
f(8) = 26 + 4 = 30
f(9) = 30 + 4 = 34
f(10) = 34 + 4 = 38