Because y 1 is proportional to x, let the proportional coefficient be k 1, then y1= k1* x;

Y2 is inversely proportional to X. If the proportional coefficient is k2, Y2 = K2/x;

So y = (k1* x)+(k2/x);

When x=3, y=8 and x=6, y= 13. The binary linear equation obtained by substitution is as follows:

3k 1+k2/3=8

6k 1+k2/6= 13

K 1=2, k2=6, so the analytical formula of function Y with independent variable X is y=2x+6/x (x≠0).