zs

English

Español

Português

Français

Deutsch

Italiano

Русский

中文(简体)

한국어

日本語

Tiếng Việt

עברית

العربية

受欢迎的三角函数 >

sin(x)+cos(x)=1.2

解答

sin (x) + cos (x) = 1.2

解答

x = 1.01319 \dots + 2 πn - \frac{π}{4}, x = π - 1.01319 \dots + 2 πn - \frac{π}{4}

+1

度数

x = 13.05194 \dots^{\circ} + 36 0^{\circ} n, x = 76.94805 \dots^{\circ} + 36 0^{\circ} n

求解步骤

sin (x) + cos (x) = 1.2

使用三角恒等式改写

sin (x) + cos (x)

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

sin (x) + cos (x)

改写为

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

使用以下普通恒等式:

cos (\frac{π}{4}) = \frac{1}{2}

使用以下普通恒等式:

sin (\frac{π}{4}) = \frac{1}{2}

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

使用角和恒等式:

sin (s + t) = sin (s) cos (t) + cos (s) sin (t)

= 2 sin (x + \frac{π}{4})

= 2 sin (x + \frac{π}{4})

2 sin (x + \frac{π}{4}) = 1.2

两边除以

2

2 sin (x + \frac{π}{4}) = 1.2

两边除以

2

\frac{2 sin ( x + \frac{π}{4} )}{2} = \frac{1.2}{2}

化简

\frac{2 sin ( x + \frac{π}{4} )}{2} = \frac{1.2}{2}

化简

\frac{2 sin ( x + \frac{π}{4} )}{2} : sin (x + \frac{π}{4})

\frac{2 sin ( x + \frac{π}{4} )}{2}

约分:

2

= sin (x + \frac{π}{4})

化简

\frac{1.2}{2} : 0.84852 \dots

\frac{1.2}{2}

转换为小数形式

2 = 1.41421 \dots

= \frac{1.2}{1.41421 \dots}

数字相除:

\frac{1.2}{1.41421 \dots} = 0.84852 \dots

= 0.84852 \dots

sin (x + \frac{π}{4}) = 0.84852 \dots

sin (x + \frac{π}{4}) = 0.84852 \dots

sin (x + \frac{π}{4}) = 0.84852 \dots

使用反三角函数性质

sin (x + \frac{π}{4}) = 0.84852 \dots

sin (x + \frac{π}{4}) = 0.84852 \dots

的通解

sin (x) = a \Rightarrow x = arcsin (a) + 2 πn, x = π - arcsin (a) + 2 πn

x + \frac{π}{4} = arcsin (0.84852 \dots) + 2 πn, x + \frac{π}{4} = π - arcsin (0.84852 \dots) + 2 πn

x + \frac{π}{4} = arcsin (0.84852 \dots) + 2 πn, x + \frac{π}{4} = π - arcsin (0.84852 \dots) + 2 πn

解

x + \frac{π}{4} = arcsin (0.84852 \dots) + 2 πn : x = arcsin (0.84852 \dots) + 2 πn - \frac{π}{4}

x + \frac{π}{4} = arcsin (0.84852 \dots) + 2 πn

将

\frac{π}{4}

到右边

x + \frac{π}{4} = arcsin (0.84852 \dots) + 2 πn

两边减去

\frac{π}{4}

x + \frac{π}{4} - \frac{π}{4} = arcsin (0.84852 \dots) + 2 πn - \frac{π}{4}

化简

x = arcsin (0.84852 \dots) + 2 πn - \frac{π}{4}

x = arcsin (0.84852 \dots) + 2 πn - \frac{π}{4}

解

x + \frac{π}{4} = π - arcsin (0.84852 \dots) + 2 πn : x = π - arcsin (0.84852 \dots) + 2 πn - \frac{π}{4}

x + \frac{π}{4} = π - arcsin (0.84852 \dots) + 2 πn

将

\frac{π}{4}

到右边

x + \frac{π}{4} = π - arcsin (0.84852 \dots) + 2 πn

两边减去

\frac{π}{4}

x + \frac{π}{4} - \frac{π}{4} = π - arcsin (0.84852 \dots) + 2 πn - \frac{π}{4}

化简

x = π - arcsin (0.84852 \dots) + 2 πn - \frac{π}{4}

x = π - arcsin (0.84852 \dots) + 2 πn - \frac{π}{4}

x = arcsin (0.84852 \dots) + 2 πn - \frac{π}{4}, x = π - arcsin (0.84852 \dots) + 2 πn - \frac{π}{4}

以小数形式表示解

x = 1.01319 \dots + 2 πn - \frac{π}{4}, x = π - 1.01319 \dots + 2 πn - \frac{π}{4}

作图

流行的例子

30cos(30x)+14=-16

30 cos (30 x) + 14 = - 16

solvefor x,cot(-x)cos(-x)+sin(-x)=-1/f

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

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

10cos^2(x)+5cos(x)-5=0

10 cos^{2} (x) + 5 cos (x) - 5 = 0

2sin(x)=-sqrt(3)

2 sin (x) = - 3