cos(A)=0.65

解答

cos (A) = 0.65

A = 0.86321 \dots + 2 πn, A = 2 π - 0.86321 \dots + 2 πn

度数

A = 49.45839 \dots^{\circ} + 36 0^{\circ} n, A = 310.54160 \dots^{\circ} + 36 0^{\circ} n

求解步骤

cos (A) = 0.65

使用反三角函数性质

cos (A) = 0.65

cos (A) = 0.65

的通解

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

A = arccos (0.65) + 2 πn, A = 2 π - arccos (0.65) + 2 πn

A = arccos (0.65) + 2 πn, A = 2 π - arccos (0.65) + 2 πn

以小数形式表示解

A = 0.86321 \dots + 2 πn, A = 2 π - 0.86321 \dots + 2 πn

sin (3 x - \frac{π}{4}) = \frac{2}{2}

sin (2 θ) = \frac{- 3}{4}, \frac{3 π}{2} \leq 2 θ \leq 2 π

3 cot (x - 1 0^{\circ}) = 4

2.4638 cos (x) = 2.5843

tan^{2} (x) = 2 tan (x) + 2 tan^{3} (x)