Q. If f(1)=2,f(2)=5 and f(n)=3f(n−1)−2f(n−2) then find the value of f(5).Answer:
Find f(3): Use the given recursive formula to find f(3). The recursive formula is f(n)=3f(n−1)−2f(n−2). We know f(1)=2 and f(2)=5. Calculate f(3) using f(2) and f(1). f(3)=3f(2)−2f(1)=3×5−2×2=15−4=11.
Find f(4): Use the recursive formula to find f(4). Now that we have f(3), we can use it along with f(2) to find f(4). f(4)=3f(3)−2f(2)=3×11−2×5=33−10=23.
Find f(5): Use the recursive formula to find f(5).Now that we have f(4) and f(3), we can find f(5).f(5)=3f(4)−2f(3)=3×23−2×11=69−22=47.
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