Please use C programming not C++

For the equation: f(x) = xe^x; Take delta x = 0.1, delta x = 0.2 and calculate the forward, backward and central differentiations of the first and second order at x_i = 2.5. For the equation: f(x) = xe^x; Take delta x = 0.1, delta x = 0.2 and calculate the forward, backward and central differentiations of the first and second order at x_i = 2.5