Come si trova f (x + h) per la funzione #f (x) = x ^ 2 - 2x + 5 #?

To find f(x+h) substitute x = x + h into the function.

#f(color(red)(x+h))=(color(red)(x+h))^2-2(color(red)(x+h))+5#

now distribute the brackets

#f(x+h)=x^2+2hx+h^2-2x-2h+5#

which may be expressed as

#f(x+h)=x^2+2x(h-1)+h^2-2h+5#