Answer:
f(n) = -11 + 22(n - 1)
f(1) is your initial value.
f(1) = -11 + 22(1 - 1)
f(1) = -11
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f(2) = -11 + 22(2 - 1) = 11
f(3) = -11 + 22(3 - 1) = 33
f(4) = -11 + 22(4 - 1) = 55
f(n - 1) is just a notation for the previous term
Using the equation f(n) = f(n - 1) + _______ :
f(2) = f(1) + ??? = 11
f(3) = f(2) + ??? = 33
f(4) = f(3) + ??? = 55
f(2) = -11 + ??? = 11
f(3) = 11 + ??? = 33
f(4) = 33 + ??? = 55
f(2) = -11 + 22 = 11
f(3) = 11 + 22 = 33
f(4) = 33 + 22 = 55
∴ f(n) = f(n - 1) + 22
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