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 >

x=(20)/(sin(45))

解答

x = \frac{20}{sin ( 4 5 ^{\circ} )}

解答

x = 202

+1

十进制

x = 28.28427 \dots

求解步骤

x = \frac{20}{sin ( 4 5 ^{\circ} )}

化简

\frac{20}{sin ( 4 5 ^{\circ} )} : 202

\frac{20}{sin ( 4 5 ^{\circ} )}

sin (4 5^{\circ}) = \frac{2}{2}

sin (4 5^{\circ})

使用以下普通恒等式:

sin (4 5^{\circ}) = \frac{2}{2}

sin (x)

周期表（周期为

36 0^{\circ} n

"）：

x 0 3 0^{\circ} 4 5^{\circ} 6 0^{\circ} 9 0^{\circ} 12 0^{\circ} 13 5^{\circ} 15 0^{\circ} sin (x) 0 \frac{1}{2} \frac{2}{2} \frac{3}{2} 1 \frac{3}{2} \frac{2}{2} \frac{1}{2} x 18 0^{\circ} 21 0^{\circ} 22 5^{\circ} 24 0^{\circ} 27 0^{\circ} 30 0^{\circ} 31 5^{\circ} 33 0^{\circ} sin (x) 0 - \frac{1}{2} - \frac{2}{2} - \frac{3}{2} - 1 - \frac{3}{2} - \frac{2}{2} - \frac{1}{2}

= \frac{2}{2}

= \frac{20}{\frac{2}{2}}

化简

\frac{20}{\frac{2}{2}}

使用分式法则:

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

= \frac{20 \cdot 2}{2}

数字相乘:

20 \cdot 2 = 40

= \frac{40}{2}

分解

40 : 2^{3} \cdot 5

因式分解

40 = 2^{3} \cdot 5

= \frac{2 ^{3} \cdot 5}{2}

消掉

\frac{2 ^{3} \cdot 5}{2} : 5 \cdot 2^{\frac{5}{2}}

\frac{2 ^{3} \cdot 5}{2}

使用根式运算法则:

n a = a^{\frac{1}{n}}

2 = 2^{\frac{1}{2}}

= \frac{2 ^{3} \cdot 5}{2 ^{\frac{1}{2}}}

使用指数法则:

\frac{x ^{a}}{x ^{b}} = x^{a - b}

\frac{2 ^{3}}{2 ^{\frac{1}{2}}} = 2^{3 - \frac{1}{2}}

= 5 \cdot 2^{- \frac{1}{2} + 3}

数字相减:

3 - \frac{1}{2} = \frac{5}{2}

= 5 \cdot 2^{\frac{5}{2}}

= 5 \cdot 2^{\frac{5}{2}}

2^{\frac{5}{2}} = 2^{2} 2

2^{\frac{5}{2}}

2^{\frac{5}{2}} = 2^{2 + \frac{1}{2}}

= 2^{2 + \frac{1}{2}}

使用指数法则:

x^{a + b} = x^{a} x^{b}

= 2^{2} \cdot 2^{\frac{1}{2}}

整理后得

= 2^{2} 2

= 5 \cdot 2^{2} 2

2^{2} = 4

= 5 \cdot 42

数字相乘:

5 \cdot 4 = 20

= 202

x = 202

x = 202

作图

流行的例子

证明 sin^4(u)-cos^4(u)=2sin^2(u)-1

p ro v e sin^{4} (u) - cos^{4} (u) = 2 sin^{2} (u) - 1

证明 tan^4(x)-sec^4(x)=-2sec^2(x)+1

p ro v e tan^{4} (x) - sec^{4} (x) = - 2 sec^{2} (x) + 1

证明 (tan(x)+cot(x))tan(x)=sec^2(x)

p ro v e (tan (x) + cot (x)) tan (x) = sec^{2} (x)

证明 (cos(x)+sin(x))^2-2sin(x)cos(x)=1

p ro v e (cos (x) + sin (x))^{2} - 2 sin (x) cos (x) = 1

证明 1-cos^2(x)=(tan^2(x))/(sec^2(x))

p ro v e 1 - cos^{2} (x) = \frac{tan ^{2} ( x )}{sec ^{2} ( x )}