Expression 2: "y" equals "f" left parenthesis, "x" , right parenthesisy=fx
2
Expression 3: left parenthesis, negative "x" sin left parenthesis, "t" , right parenthesis plus "y" cos left parenthesis, "t" , right parenthesis , right parenthesis equals "f" left parenthesis, "x" cos left parenthesis, "t" , right parenthesis plus "y" sin left parenthesis, "t" , right parenthesis , right parenthesis−xsint+ycost=fxcost+ysint