已知函数F(x)=根3sin(wx+U)-cos(wx+u)(w>0,0π)为奇函数,且函数Y=f(x)两相邻对称轴距离2分之π求,(1)U的值写f(x)解析式.(2)设a,b,c,为三角形ABC的三个内角ABC对的边,若sinA=3分之二倍根2,f(2分之B
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![已知函数F(x)=根3sin(wx+U)-cos(wx+u)(w>0,0π)为奇函数,且函数Y=f(x)两相邻对称轴距离2分之π求,(1)U的值写f(x)解析式.(2)设a,b,c,为三角形ABC的三个内角ABC对的边,若sinA=3分之二倍根2,f(2分之B](/uploads/image/z/3857498-26-8.jpg?t=%E5%B7%B2%E7%9F%A5%E5%87%BD%E6%95%B0F%EF%BC%88x%EF%BC%89%3D%E6%A0%B93sin%28wx%2BU%29-cos%EF%BC%88wx%2Bu%EF%BC%89%EF%BC%88w%3E0%2C0%CF%80%EF%BC%89%E4%B8%BA%E5%A5%87%E5%87%BD%E6%95%B0%2C%E4%B8%94%E5%87%BD%E6%95%B0Y%3Df%28x%29%E4%B8%A4%E7%9B%B8%E9%82%BB%E5%AF%B9%E7%A7%B0%E8%BD%B4%E8%B7%9D%E7%A6%BB2%E5%88%86%E4%B9%8B%CF%80%E6%B1%82%2C%EF%BC%881%EF%BC%89U%E7%9A%84%E5%80%BC%E5%86%99f%28x%29%E8%A7%A3%E6%9E%90%E5%BC%8F.%282%29%E8%AE%BEa%2Cb%2Cc%2C%E4%B8%BA%E4%B8%89%E8%A7%92%E5%BD%A2ABC%E7%9A%84%E4%B8%89%E4%B8%AA%E5%86%85%E8%A7%92ABC%E5%AF%B9%E7%9A%84%E8%BE%B9%2C%E8%8B%A5sinA%3D3%E5%88%86%E4%B9%8B%E4%BA%8C%E5%80%8D%E6%A0%B92%2Cf%EF%BC%882%E5%88%86%E4%B9%8BB)
已知函数F(x)=根3sin(wx+U)-cos(wx+u)(w>0,0π)为奇函数,且函数Y=f(x)两相邻对称轴距离2分之π求,(1)U的值写f(x)解析式.(2)设a,b,c,为三角形ABC的三个内角ABC对的边,若sinA=3分之二倍根2,f(2分之B
已知函数F(x)=根3sin(wx+U)-cos(wx+u)(w>0,0π)为奇函数,且函数Y=f(x)两相邻对称轴距离2分之π
求,(1)U的值写f(x)解析式.(2)设a,b,c,为三角形ABC的三个内角ABC对的边,若sinA=3分之二倍根2,f(2分之B)=1求边长a. 谢了,求助
已知函数F(x)=根3sin(wx+U)-cos(wx+u)(w>0,0π)为奇函数,且函数Y=f(x)两相邻对称轴距离2分之π求,(1)U的值写f(x)解析式.(2)设a,b,c,为三角形ABC的三个内角ABC对的边,若sinA=3分之二倍根2,f(2分之B
1、f(x)=√3sin(wx+u)-cos(wx+u)=2[√3/2*sin(wx+u)-1/2cos(wx+u)]=2sin(wx+u-π/6)
对于函数sin(wx+u-π/6),两相邻对称轴距离为半周期,即T/2=1/2*2π/w=π/2,∴w=2
又f(x)为奇函数,即f(-x)=-f(x),即√3sin(-wx+u)-cos(-wx+u)=-√3sin(wx+u)+cos(wx+u)
即-√3sin(wx)cosu+√3cos(-wx)sinu-cos(-wx)cosu-sin(wx)sinu
=-√3sin(wx)cosu-√3cos(wx)sinu+cos(wx)cosu-sin(wx)sinu
即2√3cos(wx)sinu-2cos(wx)cosu=0,即√3/2sinu-1/2cosu=sin(u-π/6)=0
∴u-π/6=kπ,又0