Linear function; Y=kx+b (k is not equal to zero and kb is an arbitrary real number); Y=kx(k is not equal to 0, k is an arbitrary real number) inverse proportional function; Y=k/x (x is not equal to 0 and k is an arbitrary real number and not equal to 0) quadratic function y = ax 2; +bx+c(a is not equal to zero, and a, b and c are constants) Vertex: y = a (x-h) 2+k or y = a (x+m) 2+k intersect (intersect with X axis): y = a (x-x 1) (x-x