Q. {f(1)=0f(n)=f(n−1)+2Find an explicit formula for f(n).f(n)=
Given Base Case and Recursive Formula: We are given the base case f(1)=0 and the recursive formula f(n)=f(n−1)+2. To find an explicit formula, we need to see how the function behaves as n increases.
Calculate First Few Values: Let's calculate the first few values of the function to identify a pattern:f(1)=0 (given)f(2)=f(1)+2=0+2=2f(3)=f(2)+2=2+2=4f(4)=f(3)+2=4+2=6We can see that each time n increases by 1, the function value increases by 2.
Identify Pattern: From the pattern, we can infer that f(n) increases by 2 for each increment in n starting from f(1). So, we can express f(n) as 2 times the number of increments from 1 to n. Since f(1)=0, the number of increments from 1 to n is 21.
Infer Increment Relationship: Therefore, the explicit formula for f(n) is f(n)=2×(n−1).
Verify Formula: Let's verify the formula with the base case and one other value:For n=1, f(1)=2×(1−1)=2×0=0, which matches the given base case.For n=3, f(3)=2×(3−1)=2×2=4, which matches the value we calculated earlier.
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