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受欢迎的三角函数 >

cos(x/3)= 1/2

解答

cos (\frac{x}{3}) = \frac{1}{2}

解答

x = π + 6 πn, x = 5 π + 6 πn

+1

度数

x = 18 0^{\circ} + 108 0^{\circ} n, x = 90 0^{\circ} + 108 0^{\circ} n

求解步骤

cos (\frac{x}{3}) = \frac{1}{2}

cos (\frac{x}{3}) = \frac{1}{2}

的通解

cos (x)

周期表（周期为

2 πn

）：

x 0 \frac{π}{6} \frac{π}{4} \frac{π}{3} \frac{π}{2} \frac{2 π}{3} \frac{3 π}{4} \frac{5 π}{6} cos (x) 1 \frac{3}{2} \frac{2}{2} \frac{1}{2} 0 - \frac{1}{2} - \frac{2}{2} - \frac{3}{2} x π \frac{7 π}{6} \frac{5 π}{4} \frac{4 π}{3} \frac{3 π}{2} \frac{5 π}{3} \frac{7 π}{4} \frac{11 π}{6} cos (x) - 1 - \frac{3}{2} - \frac{2}{2} - \frac{1}{2} 0 \frac{1}{2} \frac{2}{2} \frac{3}{2}

\frac{x}{3} = \frac{π}{3} + 2 πn, \frac{x}{3} = \frac{5 π}{3} + 2 πn

\frac{x}{3} = \frac{π}{3} + 2 πn, \frac{x}{3} = \frac{5 π}{3} + 2 πn

解

\frac{x}{3} = \frac{π}{3} + 2 πn : x = π + 6 πn

\frac{x}{3} = \frac{π}{3} + 2 πn

在两边乘以

3

\frac{x}{3} = \frac{π}{3} + 2 πn

在两边乘以

3

\frac{3 x}{3} = 3 \cdot \frac{π}{3} + 3 \cdot 2 πn

化简

\frac{3 x}{3} = 3 \cdot \frac{π}{3} + 3 \cdot 2 πn

化简

\frac{3 x}{3} : x

\frac{3 x}{3}

数字相除:

\frac{3}{3} = 1

= x

化简

3 \cdot \frac{π}{3} + 3 \cdot 2 πn : π + 6 πn

3 \cdot \frac{π}{3} + 3 \cdot 2 πn

3 \cdot \frac{π}{3} = π

3 \cdot \frac{π}{3}

分式相乘:

a \cdot \frac{b}{c} = \frac{a \cdot b}{c}

= \frac{π 3}{3}

约分:

3

= π

3 \cdot 2 πn = 6 πn

3 \cdot 2 πn

数字相乘:

3 \cdot 2 = 6

= 6 πn

= π + 6 πn

x = π + 6 πn

x = π + 6 πn

x = π + 6 πn

解

\frac{x}{3} = \frac{5 π}{3} + 2 πn : x = 5 π + 6 πn

\frac{x}{3} = \frac{5 π}{3} + 2 πn

在两边乘以

3

\frac{x}{3} = \frac{5 π}{3} + 2 πn

在两边乘以

3

\frac{3 x}{3} = 3 \cdot \frac{5 π}{3} + 3 \cdot 2 πn

化简

\frac{3 x}{3} = 3 \cdot \frac{5 π}{3} + 3 \cdot 2 πn

化简

\frac{3 x}{3} : x

\frac{3 x}{3}

数字相除:

\frac{3}{3} = 1

= x

化简

3 \cdot \frac{5 π}{3} + 3 \cdot 2 πn : 5 π + 6 πn

3 \cdot \frac{5 π}{3} + 3 \cdot 2 πn

3 \cdot \frac{5 π}{3} = 5 π

3 \cdot \frac{5 π}{3}

分式相乘:

a \cdot \frac{b}{c} = \frac{a \cdot b}{c}

= \frac{5 π 3}{3}

约分:

3

= 5 π

3 \cdot 2 πn = 6 πn

3 \cdot 2 πn

数字相乘:

3 \cdot 2 = 6

= 6 πn

= 5 π + 6 πn

x = 5 π + 6 πn

x = 5 π + 6 πn

x = 5 π + 6 πn

x = π + 6 πn, x = 5 π + 6 πn

作图

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