How do you find the zeros of the function ##f(x)= x^2-2x-4##?

The zeros of this function are ##x_1=1-sqrt(5)## and ##x_2=1+sqrt(5)##

To find the zeros of a quadratic function you first have to calculate ##Delta##. In this case it is ##Delta = (-2)^2-4*1*(-4) = 20## ##Delta > 0 ## so function has 2 real zeros which can be calculated using:

##x_1=(-b-sqrt(Delta))/(2a)## and ##x_2 = (-b+sqrt(Delta))/(2a)##