Review the incomplete steps in the derivation of the tangent sum identity. A 2-column table with 5 rows. Column 1 has entries Step 1: Original expression, step 2: rewrite using the definition of tangent, step 3: apply the sine sum identity and cosine sum identity, step 4: question mark, step 5: simplify using the definition of tangent. Column 2 has entries tangent (x + y), StartFraction sine (x + y) Over cosine (x + y) EndFraction, StartFraction sine (x) cosine (y) + cosine (x) sine (y) Over cosine (x) cosine (y) minus sine (x) sine (y) EndFraction, blank, StartFraction tangent (x) + tangent (y) Over 1 minus tangent (x) tangent (y) EndFraction.
Which action can be taken to the expression in Step 3 to give an expression for Step 4?
divide both the numerator and denominator by sin(x)sin(y)
divide both the numerator and denominator by sin(x)cos(y)
divide both the numerator and denominator by cos(x)sin(y)
divide both the numerator and denominator by cos(x)cos(y)