cos(x)=-0.1235,0<= x<= 2pi

解答

cos (x) = - 0.1235, 0 \leq x \leq 2 π

x = 1.69461 \dots, x = 4.58857 \dots

度数

x = 97.09414 \dots^{\circ}, x = 262.90585 \dots^{\circ}

求解步骤

cos (x) = - 0.1235, 0 \leq x \leq 2 π

使用反三角函数性质

cos (x) = - 0.1235

cos (x) = - 0.1235

的通解

cos (x) = - a \Rightarrow x = arccos (- a) + 2 πn, x = - arccos (- a) + 2 πn

x = arccos (- 0.1235) + 2 πn, x = - arccos (- 0.1235) + 2 πn

x = arccos (- 0.1235) + 2 πn, x = - arccos (- 0.1235) + 2 πn

在

0 \leq x \leq 2 π

范围内的解

x = 1.69461 \dots, x = 4.58857 \dots

sin (\frac{3 π}{x}) = 0

so l v e f or x, (sin (x) - lo g_{3} (12)) = 20

tan (θ) = - \frac{7}{5}, \frac{π}{2} < θ < π, cos (2 θ)

cos (θ) = - (\frac{1}{2})

cos (θ) = 2 cos (θ) - 1