解答
6tan6(x)1=6sec6(x)1
解答
x∈R无解
求解步骤
6tan6(x)1=6sec6(x)1
两边减去 6sec6(x)16tan6(x)1−6sec6(x)1=0
化简 6tan6(x)1−6sec6(x)1:6tan6(x)sec6(x)sec6(x)−tan6(x)
6tan6(x)1−6sec6(x)1
6tan6(x),6sec6(x)的最小公倍数:6tan6(x)sec6(x)
6tan6(x),6sec6(x)
最小公倍数 (LCM)
6,6的最小公倍数:6
6,6
最小公倍数 (LCM)
6质因数分解:2⋅3
6
6除以 26=3⋅2=2⋅3
2,3 都是质数,因此无法进一步因数分解=2⋅3
6质因数分解:2⋅3
6
6除以 26=3⋅2=2⋅3
2,3 都是质数,因此无法进一步因数分解=2⋅3
将每个因子乘以它在 6 或 6中出现的最多次数=2⋅3
数字相乘:2⋅3=6=6
计算出由出现在 6tan6(x) 或 6sec6(x)中的因子组成的表达式=6tan6(x)sec6(x)
根据最小公倍数调整分式
将每个分子乘以其分母转变为最小公倍数所要乘以的同一数值 6tan6(x)sec6(x)
对于 6tan6(x)1:将分母和分子乘以 sec6(x)6tan6(x)1=6tan6(x)sec6(x)1⋅sec6(x)=6tan6(x)sec6(x)sec6(x)
对于 6sec6(x)1:将分母和分子乘以 tan6(x)6sec6(x)1=6sec6(x)tan6(x)1⋅tan6(x)=6tan6(x)sec6(x)tan6(x)
=6tan6(x)sec6(x)sec6(x)−6tan6(x)sec6(x)tan6(x)
因为分母相等,所以合并分式: ca±cb=ca±b=6tan6(x)sec6(x)sec6(x)−tan6(x)
6tan6(x)sec6(x)sec6(x)−tan6(x)=0
g(x)f(x)=0⇒f(x)=0sec6(x)−tan6(x)=0
分解 sec6(x)−tan6(x):(sec(x)+tan(x))(sec2(x)−sec(x)tan(x)+tan2(x))(sec(x)−tan(x))(sec2(x)+sec(x)tan(x)+tan2(x))
sec6(x)−tan6(x)
将 sec6(x)−tan6(x) 改写为 (sec3(x))2−(tan3(x))2
sec6(x)−tan6(x)
使用指数法则: abc=(ab)csec6(x)=(sec3(x))2=(sec3(x))2−tan6(x)
使用指数法则: abc=(ab)ctan6(x)=(tan3(x))2=(sec3(x))2−(tan3(x))2
=(sec3(x))2−(tan3(x))2
使用平方差公式: x2−y2=(x+y)(x−y)(sec3(x))2−(tan3(x))2=(sec3(x)+tan3(x))(sec3(x)−tan3(x))=(sec3(x)+tan3(x))(sec3(x)−tan3(x))
分解 sec3(x)+tan3(x):(sec(x)+tan(x))(sec2(x)−sec(x)tan(x)+tan2(x))
sec3(x)+tan3(x)
使用立方和公式: x3+y3=(x+y)(x2−xy+y2)sec3(x)+tan3(x)=(sec(x)+tan(x))(sec2(x)−sec(x)tan(x)+tan2(x))=(sec(x)+tan(x))(sec2(x)−sec(x)tan(x)+tan2(x))
=(sec(x)+tan(x))(sec2(x)−sec(x)tan(x)+tan2(x))(sec3(x)−tan3(x))
分解 sec3(x)−tan3(x):(sec(x)−tan(x))(sec2(x)+sec(x)tan(x)+tan2(x))
sec3(x)−tan3(x)
使用立方差公式: x3−y3=(x−y)(x2+xy+y2)sec3(x)−tan3(x)=(sec(x)−tan(x))(sec2(x)+sec(x)tan(x)+tan2(x))=(sec(x)−tan(x))(sec2(x)+sec(x)tan(x)+tan2(x))
=(sec(x)+tan(x))(sec2(x)−sec(x)tan(x)+tan2(x))(sec(x)−tan(x))(sec2(x)+sec(x)tan(x)+tan2(x))
(sec(x)+tan(x))(sec2(x)−sec(x)tan(x)+tan2(x))(sec(x)−tan(x))(sec2(x)+sec(x)tan(x)+tan2(x))=0
使用三角恒等式改写
(sec(x)+tan(x))(sec2(x)−sec(x)tan(x)+tan2(x))(sec(x)−tan(x))(sec2(x)+sec(x)tan(x)+tan2(x))
(sec(x)+tan(x))(sec(x)−tan(x))=1
(sec(x)+tan(x))(sec(x)−tan(x))
乘开 (sec(x)+tan(x))(sec(x)−tan(x)):sec2(x)−tan2(x)
(sec(x)+tan(x))(sec(x)−tan(x))
使用平方差公式: (a+b)(a−b)=a2−b2a=sec(x),b=tan(x)=sec2(x)−tan2(x)
=sec2(x)−tan2(x)
使用毕达哥拉斯恒等式: sec2(x)=tan2(x)+1sec2(x)−tan2(x)=1=1
=1⋅(sec2(x)+tan2(x)+sec(x)tan(x))(sec2(x)+tan2(x)−sec(x)tan(x))
化简 1⋅(sec2(x)+tan2(x)+sec(x)tan(x))(sec2(x)+tan2(x)−sec(x)tan(x)):(sec2(x)+tan2(x)+sec(x)tan(x))(sec2(x)+tan2(x)−sec(x)tan(x))
1⋅(sec2(x)+tan2(x)+sec(x)tan(x))(sec2(x)+tan2(x)−sec(x)tan(x))
乘以:1⋅(sec2(x)+tan2(x)+sec(x)tan(x))=(sec2(x)+tan2(x)+sec(x)tan(x))=(sec2(x)+tan2(x)+sec(x)tan(x))(sec2(x)+tan2(x)−sec(x)tan(x))
=(sec2(x)+tan2(x)+sec(x)tan(x))(sec2(x)+tan2(x)−sec(x)tan(x))
(sec2(x)+tan2(x)+sec(x)tan(x))(sec2(x)+tan2(x)−sec(x)tan(x))=0
分别求解每个部分sec2(x)+tan2(x)+sec(x)tan(x)=0orsec2(x)+tan2(x)−sec(x)tan(x)=0
sec2(x)+tan2(x)+sec(x)tan(x)=0:无解
sec2(x)+tan2(x)+sec(x)tan(x)=0
用 sin, cos 表示
sec2(x)+tan2(x)+sec(x)tan(x)
使用基本三角恒等式: sec(x)=cos(x)1=(cos(x)1)2+tan2(x)+cos(x)1tan(x)
使用基本三角恒等式: tan(x)=cos(x)sin(x)=(cos(x)1)2+(cos(x)sin(x))2+cos(x)1⋅cos(x)sin(x)
化简 (cos(x)1)2+(cos(x)sin(x))2+cos(x)1⋅cos(x)sin(x):cos2(x)1+sin2(x)+sin(x)
(cos(x)1)2+(cos(x)sin(x))2+cos(x)1⋅cos(x)sin(x)
(cos(x)1)2=cos2(x)1
(cos(x)1)2
使用指数法则: (ba)c=bcac=cos2(x)12
使用法则 1a=112=1=cos2(x)1
(cos(x)sin(x))2=cos2(x)sin2(x)
(cos(x)sin(x))2
使用指数法则: (ba)c=bcac=cos2(x)sin2(x)
cos(x)1⋅cos(x)sin(x)=cos2(x)sin(x)
cos(x)1⋅cos(x)sin(x)
分式相乘: ba⋅dc=b⋅da⋅c=cos(x)cos(x)1⋅sin(x)
乘以:1⋅sin(x)=sin(x)=cos(x)cos(x)sin(x)
cos(x)cos(x)=cos2(x)
cos(x)cos(x)
使用指数法则: ab⋅ac=ab+ccos(x)cos(x)=cos1+1(x)=cos1+1(x)
数字相加:1+1=2=cos2(x)
=cos2(x)sin(x)
=cos2(x)1+cos2(x)sin2(x)+cos2(x)sin(x)
使用法则 ca±cb=ca±b=cos2(x)1+sin2(x)+sin(x)
=cos2(x)1+sin2(x)+sin(x)
cos2(x)1+sin(x)+sin2(x)=0
g(x)f(x)=0⇒f(x)=01+sin(x)+sin2(x)=0
用替代法求解
1+sin(x)+sin2(x)=0
令:sin(x)=u1+u+u2=0
1+u+u2=0:u=−21+i23,u=−21−i23
1+u+u2=0
改写成标准形式 ax2+bx+c=0u2+u+1=0
使用求根公式求解
u2+u+1=0
二次方程求根公式:
若 a=1,b=1,c=1u1,2=2⋅1−1±12−4⋅1⋅1
u1,2=2⋅1−1±12−4⋅1⋅1
化简 12−4⋅1⋅1:3i
12−4⋅1⋅1
使用法则 1a=112=1=1−4⋅1⋅1
数字相乘:4⋅1⋅1=4=1−4
数字相减:1−4=−3=−3
使用根式运算法则: −a=−1a−3=−13=−13
使用虚数运算法则: −1=i=3i
u1,2=2⋅1−1±3i
将解分隔开u1=2⋅1−1+3i,u2=2⋅1−1−3i
u=2⋅1−1+3i:−21+i23
2⋅1−1+3i
数字相乘:2⋅1=2=2−1+3i
将 2−1+3i 改写成标准复数形式:−21+23i
2−1+3i
使用分式法则: ca±b=ca±cb2−1+3i=−21+23i=−21+23i
=−21+23i
u=2⋅1−1−3i:−21−i23
2⋅1−1−3i
数字相乘:2⋅1=2=2−1−3i
将 2−1−3i 改写成标准复数形式:−21−23i
2−1−3i
使用分式法则: ca±b=ca±cb2−1−3i=−21−23i=−21−23i
=−21−23i
二次方程组的解是:u=−21+i23,u=−21−i23
u=sin(x)代回sin(x)=−21+i23,sin(x)=−21−i23
sin(x)=−21+i23,sin(x)=−21−i23
sin(x)=−21+i23:无解
sin(x)=−21+i23
无解
sin(x)=−21−i23:无解
sin(x)=−21−i23
无解
合并所有解无解
sec2(x)+tan2(x)−sec(x)tan(x)=0:无解
sec2(x)+tan2(x)−sec(x)tan(x)=0
用 sin, cos 表示
sec2(x)+tan2(x)−sec(x)tan(x)
使用基本三角恒等式: sec(x)=cos(x)1=(cos(x)1)2+tan2(x)−cos(x)1tan(x)
使用基本三角恒等式: tan(x)=cos(x)sin(x)=(cos(x)1)2+(cos(x)sin(x))2−cos(x)1⋅cos(x)sin(x)
化简 (cos(x)1)2+(cos(x)sin(x))2−cos(x)1⋅cos(x)sin(x):cos2(x)1+sin2(x)−sin(x)
(cos(x)1)2+(cos(x)sin(x))2−cos(x)1⋅cos(x)sin(x)
(cos(x)1)2=cos2(x)1
(cos(x)1)2
使用指数法则: (ba)c=bcac=cos2(x)12
使用法则 1a=112=1=cos2(x)1
(cos(x)sin(x))2=cos2(x)sin2(x)
(cos(x)sin(x))2
使用指数法则: (ba)c=bcac=cos2(x)sin2(x)
cos(x)1⋅cos(x)sin(x)=cos2(x)sin(x)
cos(x)1⋅cos(x)sin(x)
分式相乘: ba⋅dc=b⋅da⋅c=cos(x)cos(x)1⋅sin(x)
乘以:1⋅sin(x)=sin(x)=cos(x)cos(x)sin(x)
cos(x)cos(x)=cos2(x)
cos(x)cos(x)
使用指数法则: ab⋅ac=ab+ccos(x)cos(x)=cos1+1(x)=cos1+1(x)
数字相加:1+1=2=cos2(x)
=cos2(x)sin(x)
=cos2(x)1+cos2(x)sin2(x)−cos2(x)sin(x)
使用法则 ca±cb=ca±b=cos2(x)1+sin2(x)−sin(x)
=cos2(x)1+sin2(x)−sin(x)
cos2(x)1−sin(x)+sin2(x)=0
g(x)f(x)=0⇒f(x)=01−sin(x)+sin2(x)=0
用替代法求解
1−sin(x)+sin2(x)=0
令:sin(x)=u1−u+u2=0
1−u+u2=0:u=21+i23,u=21−i23
1−u+u2=0
改写成标准形式 ax2+bx+c=0u2−u+1=0
使用求根公式求解
u2−u+1=0
二次方程求根公式:
若 a=1,b=−1,c=1u1,2=2⋅1−(−1)±(−1)2−4⋅1⋅1
u1,2=2⋅1−(−1)±(−1)2−4⋅1⋅1
化简 (−1)2−4⋅1⋅1:3i
(−1)2−4⋅1⋅1
(−1)2=1
(−1)2
使用指数法则: (−a)n=an,若 n 是偶数(−1)2=12=12
使用法则 1a=1=1
4⋅1⋅1=4
4⋅1⋅1
数字相乘:4⋅1⋅1=4=4
=1−4
数字相减:1−4=−3=−3
使用根式运算法则: −a=−1a−3=−13=−13
使用虚数运算法则: −1=i=3i
u1,2=2⋅1−(−1)±3i
将解分隔开u1=2⋅1−(−1)+3i,u2=2⋅1−(−1)−3i
u=2⋅1−(−1)+3i:21+i23
2⋅1−(−1)+3i
使用法则 −(−a)=a=2⋅11+3i
数字相乘:2⋅1=2=21+3i
将 21+3i 改写成标准复数形式:21+23i
21+3i
使用分式法则: ca±b=ca±cb21+3i=21+23i=21+23i
=21+23i
u=2⋅1−(−1)−3i:21−i23
2⋅1−(−1)−3i
使用法则 −(−a)=a=2⋅11−3i
数字相乘:2⋅1=2=21−3i
将 21−3i 改写成标准复数形式:21−23i
21−3i
使用分式法则: ca±b=ca±cb21−3i=21−23i=21−23i
=21−23i
二次方程组的解是:u=21+i23,u=21−i23
u=sin(x)代回sin(x)=21+i23,sin(x)=21−i23
sin(x)=21+i23,sin(x)=21−i23
sin(x)=21+i23:无解
sin(x)=21+i23
无解
sin(x)=21−i23:无解
sin(x)=21−i23
无解
合并所有解无解
合并所有解x∈R无解