syms x1 x2 x3 x4 x5 x6 x7 dy1 dy2 dy3 dy4 dy5 dy6 dy7;
x = sym([x1,x2,x3,x4,x5,x6,x7]);
dy = sym([dy1,dy2,dy3,dy4,dy5,dy6,dy7]);
y = 174.42*(x1/x5)*(x3/(x2-x1))^0.85* ...
sqrt((1-2.62*(1-0.36*(x4/x3)^(-0.56))^(3/2)*(x4/x2)^1.16) ...
/(x6*x7));
for i = 1:7
dy(i) = inline(char(diff(y,x(i))));
end