Expression 3: cosine left parenthesis, "x" Superscript, 2 , Baseline plus "y" squared , right parenthesis equals left parenthesis, StartFraction, "x" Over "y" , EndFraction , right parenthesis squaredcosx2+y2=xy2
3
Expression 4: sine left parenthesis, "x" Superscript, 2 , Baseline minus "y" squared , right parenthesis equals left parenthesis, "x" "y" , right parenthesis squaredsinx2−y2=xy2
4
Expression 5: tangent left parenthesis, "x" Superscript, 2 , Baseline plus "y" squared , right parenthesis equals left parenthesis, StartFraction, "x" Over "y" , EndFraction , right parenthesis squaredtanx2+y2=xy2