Question

Represente em um ciclo trigonométrico o arco de 45°. Lembrando que
sen 45° = cos 45° = V2/2 determine:


a) sen 135° b) sen 315° c) cos 225° d) cos 315

Answer 1

$a)~\mathsf{sen(135^{\circ})=sen(45^{\circ})=\dfrac{\sqrt{2}}{2}}\\b)~\mathsf{sen(315^{\circ})=-sen(45^{\circ})=-\dfrac{\sqrt{2}}{2}}$

$c)~\mathsf{cos(225^{\circ})=-cos(45^{\circ})=-\dfrac{\sqrt{2}}{2}}\\d)~\mathsf{cos(315}=-cos(45^{\circ})=-\dfrac{\sqrt{2}}{2}}$