Hitunglah nilai eksak dari: a. cos 75 + cos 15 / sin 75 - sin 15 = akar 3

Trigonometri.

[tex]\displaystyle \frac{\cos A+\cos B}{\sin A-\sin B}=\cot \left ( \frac{A-B}{2} \right )\\ \frac{\cos 75^{\circ}+\cos 15^{\circ}}{\sin 75^{\circ}-\sin 15^{\circ}}=\cot \left ( \frac{75^{\circ}-15^{\circ}}{2} \right )\\ =\cot 30^{\circ}\\ =\sqrt{3}[/tex]
Terbukti.