sin(u)=-2/5

解答

sin (u) = - \frac{2}{5}

u = - 0.41151 \dots + 2 πn, u = π + 0.41151 \dots + 2 πn

度数

u = - 23.57817 \dots^{\circ} + 36 0^{\circ} n, u = 203.57817 \dots^{\circ} + 36 0^{\circ} n

求解步骤

sin (u) = - \frac{2}{5}

使用反三角函数性质

sin (u) = - \frac{2}{5}

sin (u) = - \frac{2}{5}

的通解

sin (x) = - a \Rightarrow x = arcsin (- a) + 2 πn, x = π + arcsin (a) + 2 πn

u = arcsin (- \frac{2}{5}) + 2 πn, u = π + arcsin (\frac{2}{5}) + 2 πn

u = arcsin (- \frac{2}{5}) + 2 πn, u = π + arcsin (\frac{2}{5}) + 2 πn

以小数形式表示解

u = - 0.41151 \dots + 2 πn, u = π + 0.41151 \dots + 2 πn

2 sin (3 x) cos (2 x) - cos (2 x) = 0

4 sin^{2} (x) + 2 sin (x) - 2 = 0

so l v e f or x, cos (x y) = 0

- 6 cos (x) sin (x) = 0

tan (2 x - \frac{π}{6}) = 3