Question

Como calcular SenX, CosX, TgX ?

Calcule:

Sen13$\pi$ / 2

Sen 25 $\pi \pi$ / 3

Answer 1

$\bullet\;\;\mathrm{sen\,}\dfrac{13\pi}{2}\\ \\ =\mathrm{sen}\left(\dfrac{\pi+12\pi}{2} \right )\\ \\ =\mathrm{sen}\left(\dfrac{\pi}{2}+\dfrac{12\pi}{2} \right )\\ \\ =\mathrm{sen}\left(\dfrac{\pi}{2}+6\pi \right )\\ \\ =\mathrm{sen}\left(\dfrac{\pi}{2}+3\cdot 2\pi \right )\\ \\ =\mathrm{sen\,}\dfrac{\pi}{2}\\ \\ =1$


$\bullet\;\;\mathrm{sen\,}\dfrac{25\pi}{3}\\ \\ =\mathrm{sen}\left(\dfrac{\pi+24\pi}{3} \right )\\ \\ =\mathrm{sen}\left(\dfrac{\pi}{3}+\dfrac{24\pi}{3} \right )\\ \\ =\mathrm{sen}\left(\dfrac{\pi}{3}+8\pi \right )\\ \\ =\mathrm{sen}\left(\dfrac{\pi}{3}+4\cdot 2\pi \right )\\ \\ =\mathrm{sen\,}\dfrac{\pi}{3}\\ \\ =\dfrac{\sqrt{3}}{2}$