cos(x)= 45/52

解答

cos (x) = \frac{45}{52}

x = 0.52487 \dots + 2 πn, x = 2 π - 0.52487 \dots + 2 πn

度数

x = 30.07334 \dots^{\circ} + 36 0^{\circ} n, x = 329.92665 \dots^{\circ} + 36 0^{\circ} n

求解步骤

cos (x) = \frac{45}{52}

使用反三角函数性质

cos (x) = \frac{45}{52}

cos (x) = \frac{45}{52}

的通解

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

x = arccos (\frac{45}{52}) + 2 πn, x = 2 π - arccos (\frac{45}{52}) + 2 πn

x = arccos (\frac{45}{52}) + 2 πn, x = 2 π - arccos (\frac{45}{52}) + 2 πn

以小数形式表示解

x = 0.52487 \dots + 2 πn, x = 2 π - 0.52487 \dots + 2 πn

so l v e f or x, cos (2 x) = \frac{m - 1}{m + 1}

6 tan^{2} (x) + 8 = 10

2 sin (x - \frac{π}{4}) + 2 cos (x) = 1

sin^{2} (θ) = 2 cos (θ) + 1

sin (6 x) cos (10 x) - cos (6 x) sin (10 x) = - 0.1