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受欢迎的三角函数 >

r^2=a^2(sin(x)+cos(x))

解答

r^{2} = a^{2} (sin (x) + cos (x))

解答

x = arcsin (\frac{r ^{2}}{2 a ^{2}}) + 2 πn - \frac{π}{4}, x = π + arcsin (- \frac{r ^{2}}{2 a ^{2}}) + 2 πn - \frac{π}{4}

求解步骤

r^{2} = a^{2} (sin (x) + cos (x))

交换两边

a^{2} (sin (x) + cos (x)) = r^{2}

使用三角恒等式改写

a^{2} (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})

= a^{2} 2 sin (x + \frac{π}{4})

a^{2} 2 sin (x + \frac{π}{4}) = r^{2}

两边除以

a^{2} 2; a \neq = 0

a^{2} 2 sin (x + \frac{π}{4}) = r^{2}

两边除以

a^{2} 2; a \neq = 0

\frac{a ^{2} 2 sin ( x + \frac{π}{4} )}{a ^{2} 2} = \frac{r ^{2}}{a ^{2} 2}; a \neq = 0

化简

\frac{a ^{2} 2 sin ( x + \frac{π}{4} )}{a ^{2} 2} = \frac{r ^{2}}{a ^{2} 2}

化简

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

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

约分:

a^{2}

= \frac{2 sin ( x + \frac{π}{4} )}{2}

约分:

2

= sin (x + \frac{π}{4})

化简

\frac{r ^{2}}{a ^{2} 2} : \frac{2 r ^{2}}{2 a ^{2}}

\frac{r ^{2}}{a ^{2} 2}

乘以共轭根式

\frac{2}{2}

= \frac{r ^{2} 2}{a ^{2} 2 2}

a^{2} 22 = 2 a^{2}

a^{2} 22

使用根式运算法则:

a a = a

22 = 2

= 2 a^{2}

= \frac{2 r ^{2}}{2 a ^{2}}

sin (x + \frac{π}{4}) = \frac{2 r ^{2}}{2 a ^{2}}; a \neq = 0

sin (x + \frac{π}{4}) = \frac{2 r ^{2}}{2 a ^{2}}; a \neq = 0

sin (x + \frac{π}{4}) = \frac{2 r ^{2}}{2 a ^{2}}; a \neq = 0

使用反三角函数性质

sin (x + \frac{π}{4}) = \frac{2 r ^{2}}{2 a ^{2}}

sin (x + \frac{π}{4}) = \frac{2 r ^{2}}{2 a ^{2}}

的通解

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

x + \frac{π}{4} = arcsin (\frac{2 r ^{2}}{2 a ^{2}}) + 2 πn, x + \frac{π}{4} = π + arcsin (- \frac{2 r ^{2}}{2 a ^{2}}) + 2 πn

x + \frac{π}{4} = arcsin (\frac{2 r ^{2}}{2 a ^{2}}) + 2 πn, x + \frac{π}{4} = π + arcsin (- \frac{2 r ^{2}}{2 a ^{2}}) + 2 πn

解

x + \frac{π}{4} = arcsin (\frac{2 r ^{2}}{2 a ^{2}}) + 2 πn : x = arcsin (\frac{r ^{2}}{2 a ^{2}}) + 2 πn - \frac{π}{4}

x + \frac{π}{4} = arcsin (\frac{2 r ^{2}}{2 a ^{2}}) + 2 πn

化简

arcsin (\frac{2 r ^{2}}{2 a ^{2}}) + 2 πn : arcsin (\frac{r ^{2}}{2 a ^{2}}) + 2 πn

arcsin (\frac{2 r ^{2}}{2 a ^{2}}) + 2 πn

\frac{2 r ^{2}}{2 a ^{2}} = \frac{r ^{2}}{2 a ^{2}}

\frac{2 r ^{2}}{2 a ^{2}}

使用根式运算法则:

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

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

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

使用指数法则:

\frac{x ^{a}}{x ^{b}} = \frac{1}{x ^{b - a}}

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

= \frac{r ^{2}}{2 ^{- \frac{1}{2} + 1} a ^{2}}

数字相减:

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

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

使用根式运算法则:

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

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

= \frac{r ^{2}}{2 a ^{2}}

= arcsin (\frac{r ^{2}}{2 a ^{2}}) + 2 πn

x + \frac{π}{4} = arcsin (\frac{r ^{2}}{2 a ^{2}}) + 2 πn

将

\frac{π}{4}

到右边

x + \frac{π}{4} = arcsin (\frac{r ^{2}}{2 a ^{2}}) + 2 πn

两边减去

\frac{π}{4}

x + \frac{π}{4} - \frac{π}{4} = arcsin (\frac{r ^{2}}{2 a ^{2}}) + 2 πn - \frac{π}{4}

化简

x = arcsin (\frac{r ^{2}}{2 a ^{2}}) + 2 πn - \frac{π}{4}

x = arcsin (\frac{r ^{2}}{2 a ^{2}}) + 2 πn - \frac{π}{4}

解

x + \frac{π}{4} = π + arcsin (- \frac{2 r ^{2}}{2 a ^{2}}) + 2 πn : x = π + arcsin (- \frac{r ^{2}}{2 a ^{2}}) + 2 πn - \frac{π}{4}

x + \frac{π}{4} = π + arcsin (- \frac{2 r ^{2}}{2 a ^{2}}) + 2 πn

化简

π + arcsin (- \frac{2 r ^{2}}{2 a ^{2}}) + 2 πn : π + arcsin (- \frac{r ^{2}}{2 a ^{2}}) + 2 πn

π + arcsin (- \frac{2 r ^{2}}{2 a ^{2}}) + 2 πn

\frac{2 r ^{2}}{2 a ^{2}} = \frac{r ^{2}}{2 a ^{2}}

\frac{2 r ^{2}}{2 a ^{2}}

使用根式运算法则:

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

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

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

使用指数法则:

\frac{x ^{a}}{x ^{b}} = \frac{1}{x ^{b - a}}

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

= \frac{r ^{2}}{2 ^{- \frac{1}{2} + 1} a ^{2}}

数字相减:

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

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

使用根式运算法则:

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

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

= \frac{r ^{2}}{2 a ^{2}}

= π + arcsin (- \frac{r ^{2}}{2 a ^{2}}) + 2 πn

x + \frac{π}{4} = π + arcsin (- \frac{r ^{2}}{2 a ^{2}}) + 2 πn

将

\frac{π}{4}

到右边

x + \frac{π}{4} = π + arcsin (- \frac{r ^{2}}{2 a ^{2}}) + 2 πn

两边减去

\frac{π}{4}

x + \frac{π}{4} - \frac{π}{4} = π + arcsin (- \frac{r ^{2}}{2 a ^{2}}) + 2 πn - \frac{π}{4}

化简

x = π + arcsin (- \frac{r ^{2}}{2 a ^{2}}) + 2 πn - \frac{π}{4}

x = π + arcsin (- \frac{r ^{2}}{2 a ^{2}}) + 2 πn - \frac{π}{4}

x = arcsin (\frac{r ^{2}}{2 a ^{2}}) + 2 πn - \frac{π}{4}, x = π + arcsin (- \frac{r ^{2}}{2 a ^{2}}) + 2 πn - \frac{π}{4}

作图

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