Trigonometric Equation

We extensively use of the graphs of the functions sine, cosine and tangent in order to solve these equations. In trigonometric equations, a number of angles and their trigonometric ratios are used frequently. A list of these angles and their sines, cosines, and tangents are given below.

—	$\displaystyle 0$	$\displaystyle \frac{\pi}{6}$	$\displaystyle \frac{\pi }{4}$	$\displaystyle \frac{\pi }{3}$	$\displaystyle \frac{\pi }{2}$
—	$\displaystyle {{0}^{\circ }}$	$\displaystyle {{30}^{\circ }}$	$\displaystyle {{45}^{\circ }}$	$\displaystyle {{60}^{\circ }}$	$\displaystyle {{90}^{\circ }}$
$\displaystyle \sin$	$\displaystyle 0$	$\displaystyle \frac{1}{2}$	$\displaystyle \frac{1}{{\sqrt{2}}}$	$\displaystyle \frac{{\sqrt{3}}}{2}$	$\displaystyle 1$
$\displaystyle \cos$	$\displaystyle 1$	$\displaystyle \frac{{\sqrt{3}}}{2}$	$\displaystyle \frac{1}{{\sqrt{2}}}$	$\displaystyle \frac{1}{2}$	$\displaystyle {{0}^{\circ }}$
$\displaystyle \tan$	$\displaystyle {{0}^{\circ }}$	$\displaystyle \frac{1}{{\sqrt{3}}}$	$\displaystyle 1$	$\displaystyle \sqrt{3}$	$\displaystyle \infty$