Question

If f(1)=5 and f(n)=nf(n-1)-1 then find the value of f(3)

Answer 1

$Answer: \\f(n) = nf(n - 1) - 1 \\ \Rightarrow f(2) = 2f(1) - 1 \\ \Leftrightarrow f(2) = 2 \times 5 - 1 = 10 - 1 = 9 \\\Rightarrow f(3) = 3f(2) - 1 = 3 \times 9 - 1 = 27 - 1 = 26$