Question

Trig. Use sum or difference to write the formula as a trig function

Answer 1

Solution:

Recall that from trigonometric identities:

$\tan(A-B)=\frac{\tan A-\tan B}{1+\tan A\tan B}$

Given:

This implies that by comparison,

$\begin{gathered} A=43\degree \\ B=18\degree \end{gathered}$

Thus, we have

$\begin{gathered} \tan(43-18) \\ =\tan25 \end{gathered}$

Hence, as a trigonometric function of one number, we have

$\tan25$