For f (x, y) = x cos y, if x = a, y = b, the first 4 items of Taylor power series expansion, the syntax is correct:

A、symsxyab;f=x*cos(y);F=taylor(f,[x,y],[a,b],’Order’,4);
B、symsab;f=x*cos(y);F=taylor(f,[x,y],[0,0],’Order’,4);
C、symsxyab;f=x*cos(2y);F=taylor(f,[x,y],[a,b],’Order’,4);
D、symsxy;f=x*cos(y);F=taylor(f,[x,y],[a,b],’Order’,4)