Expression 1: "f" left parenthesis, "x" , right parenthesis equals StartFraction, left parenthesis, StartNestedFraction, "c" left parenthesis, sin "x" minus cos 4 "x" , right parenthesis NestedOver cos "x" , EndNestedFraction , right parenthesis Over StartNestedFraction, "c" left parenthesis, sin "x" minus cos 4 "x" , right parenthesis NestedOver tan "x" , EndNestedFraction , EndFractionfx=csinx−cos4xcosxcsinx−cos4xtanx