cos(x)=(4.6)/(8.6)

解答

cos (x) = \frac{4.6}{8.6}

x = 1.00642 \dots + 2 πn, x = 2 π - 1.00642 \dots + 2 πn

度数

x = 57.66397 \dots^{\circ} + 36 0^{\circ} n, x = 302.33602 \dots^{\circ} + 36 0^{\circ} n

求解步骤

cos (x) = \frac{4.6}{8.6}

使用反三角函数性质

cos (x) = \frac{4.6}{8.6}

cos (x) = \frac{4.6}{8.6}

的通解

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

x = arccos (\frac{4.6}{8.6}) + 2 πn, x = 2 π - arccos (\frac{4.6}{8.6}) + 2 πn

x = arccos (\frac{4.6}{8.6}) + 2 πn, x = 2 π - arccos (\frac{4.6}{8.6}) + 2 πn

以小数形式表示解

x = 1.00642 \dots + 2 πn, x = 2 π - 1.00642 \dots + 2 πn

5 tan (x) + 5 tan^{2} (x) = 0

8 sec^{2} (x) - 8 sec (x) = 16

50 = 36 sin (\frac{2 π}{365} (t - 101)) + 14

sin (2 θ - \frac{π}{3}) = - \frac{1}{2}

7 cos (θ) + 20 = 0