Expression 6: "z" times "m" left parenthesis, "x" plus "k" "a" , "y" , right parenthesis equals "s" sine left parenthesis, 2 Superscript, "w" , Baseline "m" left parenthesis, "x" plus "k" "a" , "y" , right parenthesis , right parenthesisz·mx+ka,y=ssin2wmx+ka,y
6
Expression 7: "z" times "m" left parenthesis, "x" minus "k" "a" , "y" , right parenthesis equals "s" cosine left parenthesis, 2 Superscript, "w" , Baseline "m" left parenthesis, "x" minus "k" "a" , "y" , right parenthesis , right parenthesisz·mx−ka,y=scos2wmx−ka,y
