Write the expression as the sine, cosine, or tangent of an angle.
-$\frac { \tan 5 x - \tan 4 y } { 1 + \tan 5 x \tan 4 y }$
A) $\tan ( 5 x - 4 y )$
B) $\tan \left( \frac { 5 x - 4 y } { 2 } \right)$
C) $\tan \left( \frac { 5 x + 4 y } { 2 } \right)$
D) $\tan ( 5 x + 4 y )$

Question

Quizplus · Accepted Answer

The expression $\frac { \tan 5 x - \tan 4 y } { 1 + \tan 5 x \tan 4 y }$ is a direct application of the tangent subtraction formula, $\tan(A - B) = \frac{\tan A - \tan B}{1 + \tan A \tan B}$, making the correct answer $\tan ( 5 x - 4 y )$.

Write the Expression as the Sine, Cosine, or Tangent of an Angle