Q. If f(1)=1,f(2)=4 and f(n)=f(n−1)−3f(n−2) then find the value of f(6).Answer:
Find f(3): Use the given initial conditions to find f(3). The recursive formula is f(n)=f(n−1)−3f(n−2). We know f(1)=1 and f(2)=4. Calculate f(3) using the formula. f(3)=f(2)−3f(1)=4−3(1)=4−3=1.
Find f(4): Use the recursive formula to find f(4).Now that we have f(3), we can find f(4).f(4)=f(3)−3f(2)=1−3(4)=1−12=−11.
Find f(5): Use the recursive formula to find f(5). With f(4) found, we can now find f(5). f(5)=f(4)−3f(3)=−11−3(1)=−11−3=−14.
Find f(6): Finally, use the recursive formula to find f(6). Now we can find f(6) using f(5) and f(4). f(6)=f(5)−3f(4)=−14−3(−11)=−14+33=19.
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