解答
tan(45∘−x)+tan(x)=1
解答
x=360∘n,x=180∘+360∘n,x=45∘+180∘n
+1
弧度
x=0+2πn,x=π+2πn,x=4π+πn求解步骤
tan(45∘−x)+tan(x)=1
使用三角恒等式改写
tan(45∘−x)+tan(x)=1
使用三角恒等式改写
tan(45∘−x)
使用基本三角恒等式: tan(x)=cos(x)sin(x)=cos(45∘−x)sin(45∘−x)
使用角差恒等式: sin(s−t)=sin(s)cos(t)−cos(s)sin(t)=cos(45∘−x)sin(45∘)cos(x)−cos(45∘)sin(x)
使用角差恒等式: cos(s−t)=cos(s)cos(t)+sin(s)sin(t)=cos(45∘)cos(x)+sin(45∘)sin(x)sin(45∘)cos(x)−cos(45∘)sin(x)
化简 cos(45∘)cos(x)+sin(45∘)sin(x)sin(45∘)cos(x)−cos(45∘)sin(x):cos(x)+sin(x)cos(x)−sin(x)
cos(45∘)cos(x)+sin(45∘)sin(x)sin(45∘)cos(x)−cos(45∘)sin(x)
sin(45∘)cos(x)−cos(45∘)sin(x)=22cos(x)−22sin(x)
sin(45∘)cos(x)−cos(45∘)sin(x)
化简 sin(45∘):22
sin(45∘)
使用以下普通恒等式:sin(45∘)=22
sin(x) 周期表(周期为 360∘n"):
x030∘45∘60∘90∘120∘135∘150∘sin(x)02122231232221x180∘210∘225∘240∘270∘300∘315∘330∘sin(x)0−21−22−23−1−23−22−21
=22=22cos(x)−cos(45∘)sin(x)
化简 cos(45∘):22
cos(45∘)
使用以下普通恒等式:cos(45∘)=22
cos(x) 周期表(周期为 360∘n):
x030∘45∘60∘90∘120∘135∘150∘cos(x)12322210−21−22−23x180∘210∘225∘240∘270∘300∘315∘330∘cos(x)−1−23−22−210212223
=22=22cos(x)−22sin(x)
=cos(45∘)cos(x)+sin(45∘)sin(x)22cos(x)−22sin(x)
cos(45∘)cos(x)+sin(45∘)sin(x)=22cos(x)+22sin(x)
cos(45∘)cos(x)+sin(45∘)sin(x)
化简 cos(45∘):22
cos(45∘)
使用以下普通恒等式:cos(45∘)=22
cos(x) 周期表(周期为 360∘n):
x030∘45∘60∘90∘120∘135∘150∘cos(x)12322210−21−22−23x180∘210∘225∘240∘270∘300∘315∘330∘cos(x)−1−23−22−210212223
=22=22cos(x)+sin(45∘)sin(x)
化简 sin(45∘):22
sin(45∘)
使用以下普通恒等式:sin(45∘)=22
sin(x) 周期表(周期为 360∘n"):
x030∘45∘60∘90∘120∘135∘150∘sin(x)02122231232221x180∘210∘225∘240∘270∘300∘315∘330∘sin(x)0−21−22−23−1−23−22−21
=22=22cos(x)+22sin(x)
=22cos(x)+22sin(x)22cos(x)−22sin(x)
乘 22cos(x):22cos(x)
22cos(x)
分式相乘: a⋅cb=ca⋅b=22cos(x)
=22cos(x)+22sin(x)22cos(x)−22sin(x)
乘 22sin(x):22sin(x)
22sin(x)
分式相乘: a⋅cb=ca⋅b=22sin(x)
=22cos(x)+22sin(x)22cos(x)−22sin(x)
乘 22cos(x):22cos(x)
22cos(x)
分式相乘: a⋅cb=ca⋅b=22cos(x)
=22cos(x)+22sin(x)22cos(x)−22sin(x)
乘 22sin(x):22sin(x)
22sin(x)
分式相乘: a⋅cb=ca⋅b=22sin(x)
=22cos(x)+22sin(x)22cos(x)−22sin(x)
合并分式 22cos(x)+22sin(x):22cos(x)+2sin(x)
使用法则 ca±cb=ca±b=22cos(x)+2sin(x)
=22cos(x)+2sin(x)22cos(x)−22sin(x)
合并分式 22cos(x)−22sin(x):22cos(x)−2sin(x)
使用法则 ca±cb=ca±b=22cos(x)−2sin(x)
=22cos(x)+2sin(x)22cos(x)−2sin(x)
分式相除: dcba=b⋅ca⋅d=2(2cos(x)+2sin(x))(2cos(x)−2sin(x))⋅2
约分:2=2cos(x)+2sin(x)2cos(x)−2sin(x)
因式分解出通项 2=2cos(x)+2sin(x)2(cos(x)−sin(x))
因式分解出通项 2=2(cos(x)+sin(x))2(cos(x)−sin(x))
约分:2=cos(x)+sin(x)cos(x)−sin(x)
=cos(x)+sin(x)cos(x)−sin(x)
cos(x)+sin(x)cos(x)−sin(x)+tan(x)=1
cos(x)+sin(x)cos(x)−sin(x)+tan(x)=1
两边减去 1cos(x)+sin(x)cos(x)−sin(x)+tan(x)−1=0
化简 cos(x)+sin(x)cos(x)−sin(x)+tan(x)−1:cos(x)+sin(x)−2sin(x)+tan(x)cos(x)+tan(x)sin(x)
cos(x)+sin(x)cos(x)−sin(x)+tan(x)−1
将项转换为分式: tan(x)=cos(x)+sin(x)tan(x)(cos(x)+sin(x)),1=cos(x)+sin(x)1(cos(x)+sin(x))=cos(x)+sin(x)cos(x)−sin(x)+cos(x)+sin(x)tan(x)(cos(x)+sin(x))−cos(x)+sin(x)1⋅(cos(x)+sin(x))
因为分母相等,所以合并分式: ca±cb=ca±b=cos(x)+sin(x)cos(x)−sin(x)+tan(x)(cos(x)+sin(x))−1⋅(cos(x)+sin(x))
乘以:1⋅(cos(x)+sin(x))=(cos(x)+sin(x))=cos(x)+sin(x)cos(x)−sin(x)+tan(x)(cos(x)+sin(x))−(cos(x)+sin(x))
乘开 cos(x)−sin(x)+tan(x)(cos(x)+sin(x))−(cos(x)+sin(x)):−2sin(x)+tan(x)cos(x)+tan(x)sin(x)
cos(x)−sin(x)+tan(x)(cos(x)+sin(x))−(cos(x)+sin(x))
乘开 tan(x)(cos(x)+sin(x)):tan(x)cos(x)+tan(x)sin(x)
tan(x)(cos(x)+sin(x))
使用分配律: a(b+c)=ab+aca=tan(x),b=cos(x),c=sin(x)=tan(x)cos(x)+tan(x)sin(x)
=cos(x)−sin(x)+tan(x)cos(x)+tan(x)sin(x)−(cos(x)+sin(x))
−(cos(x)+sin(x)):−cos(x)−sin(x)
−(cos(x)+sin(x))
打开括号=−(cos(x))−(sin(x))
使用加减运算法则+(−a)=−a=−cos(x)−sin(x)
=cos(x)−sin(x)+tan(x)cos(x)+tan(x)sin(x)−cos(x)−sin(x)
化简 cos(x)−sin(x)+tan(x)cos(x)+tan(x)sin(x)−cos(x)−sin(x):−2sin(x)+tan(x)cos(x)+tan(x)sin(x)
cos(x)−sin(x)+tan(x)cos(x)+tan(x)sin(x)−cos(x)−sin(x)
同类项相加:cos(x)−cos(x)=0=−sin(x)+tan(x)cos(x)+tan(x)sin(x)−sin(x)
同类项相加:−sin(x)−sin(x)=−2sin(x)=−2sin(x)+tan(x)cos(x)+tan(x)sin(x)
=−2sin(x)+tan(x)cos(x)+tan(x)sin(x)
=cos(x)+sin(x)−2sin(x)+tan(x)cos(x)+tan(x)sin(x)
cos(x)+sin(x)−2sin(x)+tan(x)cos(x)+tan(x)sin(x)=0
g(x)f(x)=0⇒f(x)=0−2sin(x)+tan(x)cos(x)+tan(x)sin(x)=0
使用三角恒等式改写
−2sin(x)+cos(x)tan(x)+sin(x)tan(x)
cos(x)tan(x)=sin(x)
cos(x)tan(x)
使用基本三角恒等式: tan(x)=cos(x)sin(x)=cos(x)cos(x)sin(x)
化简 cos(x)cos(x)sin(x):sin(x)
cos(x)cos(x)sin(x)
分式相乘: a⋅cb=ca⋅b=cos(x)sin(x)cos(x)
约分:cos(x)=sin(x)
=sin(x)
=−2sin(x)+sin(x)+sin(x)tan(x)
化简=−sin(x)+sin(x)tan(x)
−sin(x)+sin(x)tan(x)=0
分解 −sin(x)+sin(x)tan(x):sin(x)(tan(x)−1)
−sin(x)+sin(x)tan(x)
因式分解出通项 sin(x)=sin(x)(−1+tan(x))
sin(x)(tan(x)−1)=0
分别求解每个部分sin(x)=0ortan(x)−1=0
sin(x)=0:x=360∘n,x=180∘+360∘n
sin(x)=0
sin(x)=0的通解
sin(x) 周期表(周期为 360∘n"):
x030∘45∘60∘90∘120∘135∘150∘sin(x)02122231232221x180∘210∘225∘240∘270∘300∘315∘330∘sin(x)0−21−22−23−1−23−22−21
x=0+360∘n,x=180∘+360∘n
x=0+360∘n,x=180∘+360∘n
解 x=0+360∘n:x=360∘n
x=0+360∘n
0+360∘n=360∘nx=360∘n
x=360∘n,x=180∘+360∘n
tan(x)−1=0:x=45∘+180∘n
tan(x)−1=0
将 1到右边
tan(x)−1=0
两边加上 1tan(x)−1+1=0+1
化简tan(x)=1
tan(x)=1
tan(x)=1的通解
tan(x) 周期表(周期为 180∘n):
x030∘45∘60∘90∘120∘135∘150∘tan(x)03313±∞−3−1−33
x=45∘+180∘n
x=45∘+180∘n
合并所有解x=360∘n,x=180∘+360∘n,x=45∘+180∘n