Question

If f(x) = g(x+1) and g(x) = x^2, find the value of f(3).

Answer 1

$\bf \begin{cases} f(x)=&g(x+1)\\ f(3)=&g(3+1)\\ &g(4)\\[-0.5em] \hrulefill& \hrulefill\\ g(x)=&x^2\\ g(4)=&4^2\\ &16 \end{cases}\qquad \qquad f(3)\implies g(4)\implies 16$