1. ) Este ejercicio lo resolveré como una ecuación de segundo grado ; usando la factorizacion :
<img src="https://tex.z-dn.net/?f=%7B3sen%5E2x-5senx%2B2%3D0%7D%5C%5C%5C%5C%7B%20%5Cfrac%7B%283senx-3%29%283senx-2%29%7D%7B3%7D%20%3D0%7D%5C%5C%5C%5C%7B%20%5Cfrac%7B3%28senx-1%29%283senx-2%29%7D%7B3%7D%20%3D0%7D%5C%5C%5C%5C%7B%28senx-1%29%283senx-2%29%3D0%7D%5C%5C%5C%5C%7Bsenx-1%3D0%7D%5C%5C%7Bsenx%3D1%7D%5C%5C%7Bx%3Dsen%5E%7B-1%7D1%7D%5C%5C%7B%5Cboxed%7Bx%3D90%5E%7B%5Ccirc%7D%7D%7D%5C%5C%5C%5C%7B3senx-2%3D0%7D%5C%5C%7Bsenx%3D2%2F3%7D%5C%5C%7Bx%3Dsen%5E%7B-1%7D2%2F3%7D%5C%5C%7B%5Cboxed%7Bx%3D41.81%5E%7B%5Ccirc%7D%7D" />
2.
) Este lo haré usando las identidades trigonométricas :
<img src="https://tex.z-dn.net/?f=%7B2tanx-3ctgx-1%3D0%7D%5C%5C%5C%5C%7B%20%5Cfrac%7B2senx%7D%7Bcosx%7D%20-%20%5Cfrac%7B3cosx%7D%7Bsenx%7D%20-1%3D0%7D%5C%5C%5C%5C%7B%202sen%5E2x-3cos%5E2x-senx.cosx%3D0%7D%5C%5C%5C%5C%7B2sen%5E2x-senx.cosx-3cos%5E2x%3D0%7D%5C%5C%5C%5C%7B%20%5Cfrac%7B%282sen%5E2x-3cosx%29%282senx%2B2cosx%29%7D%7B2%7D%20%3D0%7D%5C%5C%5C%5C%7B%20%5Cfrac%7B%282senx-3cosx%292%28senx%2Bcosx%29%7D%7B2%7D%20%3D0%7D%5C%5C%5C%5C%7B%282senx-3cosx%29%28senx%2Bcosx%29%3D0%7D%5C%5C%5C%5C%7Bsenx%2Bcosx%3D0%7D%5C%5C%7Bsenx%3D-cosx%7D%5C%5C%7B%5Ctext%7Bel%20%5C%27unico%20%5C%27angulo%20que%20cumple%20esta%20condici%5C%27on%20es%20el%20de%20-45%20o%20135%7D%7D" />
3.
) Para este ejercicio volveré a usar las identidades :
<img src="https://tex.z-dn.net/?f=%7Bcos%5E2x-3sen%5E2x%3D0%7D%5C%5C%5C%5C%7B1-sen%5E2-3sen%5E2x%3D0%7D%5C%5C%5C%5C%7B1-4sen%5E2x%3D0%7D%5C%5C%5C%5C%7B4sen%5E2x%3D1%7D%5C%5C%5C%5C%7Bsen%5E2x%3D%20%5Cfrac%7B1%7D%7B4%7D%20%7D%5C%5C%5C%5C%7B%20senx%3D%5Cpm%20%5Csqrt%7B%20%5Cfrac%7B1%7D%7B4%7D%20%7D%20%7D%5C%5C%5C%5C%7Bsenx%3D%5Cpm%20%5Cfrac%7B1%7D%7B2%7D%20%7D%5C%5C%5C%5C%7Bx%3Dsen%5E%7B-1%7D1%2F2%7D%5C%5C%7B%5Cboxed%7Bx%3D30%5E%7B%5Ccirc%7D%7D%7D%5C%5C%5C%5C%7Bx%3D-sen%5E%7B-1%7D1%2F2%7D%5C%5C%7B%5Cboxed%7Bx%3D-30%5E%7B%5Ccirc%7D%7D%7D%5C%5C%5C%5C%7B%5Cmathbf%7Bsalu2.%5C%20%3A%29%7D%7D%5C%5C%7B%5Cmathbf%7BWellington%7D%7D" />.