要使根号3sinx-cosx=(2k-3) (2-3k)有意义,则k属于?
来源:学生作业帮助网 编辑:作业帮 时间:2024/09/22 12:37:26
/>tanx=√3则x=kπ+π/3,k∈Z(1)k是偶数,则sinx=√3/2,cosx=1/2(2)k是奇数则sinx=√3/2,cosx=1/2(sinx+cosx)/(sinx-cosx)的值
用sinx2+cosx2=1再问:可以帮我把顺序写出吗。再问:谢谢。再答:就是3cos2x+cos2x=1再答:然后cosx=正负0.5就行了再问:就只有后面这两个步骤吧再问:还是前面那个也要再问:s
sinx+cosx=√2两边同时平方得sin²x+2sinxcosx+cos²x=21+2sinxcosx=22sinxcosx=1sinxcosx=1/2答案:1/2
F(x)=m.n=2根号3sinxcosx+cos^2x-sin^2x=根号3sin2x+cos2x=2sin(2x+π/6)
sinx+根号3cosx=22(sinx/2+根号3cosx/2)=2sinx/2+根号3cosx/2=1sinxcosπ/3+cosxsinπ/3=1sin(x+π/3)=1所以x+π/3=2kπ+
f(x)=a^2+2aba^2=1,a*b=(sinx)^2+√3sinx*cosx=1/2-1/2cos2x+√3/2sin(2x)=1/2+sin(2x-π/6)所以f(x)=1+2(1/2+si
原式=2√2(cosx*1/2-sinx*√3/2)=2√2(cosxcosπ/3-sinxsinπ/3)=2√2cos(x+π/3)
sinx+cosx=√2(sinxcosπ/4+cosxsinπ/4)=√2sin(x+π/4)sinx-cosx=√2(sinxcosπ/4-cosxsinπ/4)=√2sin(x-π/4)sinx
=2*(根号3sinx/2+cosx/2)=2(sinx*cos30°+cosxsin30°)=2sin(x+30°)
√3sinx-cosx=2(sinxcosπ/6-cosxsinπ/6)=2sin(x-π/6)
=(sinx)^2+√3sinxcosx=(1-cos2x)/2+√3/2(2sinxcosx)=1/2-1/2cosx+√3/2sin2x=1/2+sin(-π/6)cos2x+cos(-π/6)s
π/6+2kπ(k属于Z)
等于2sin(2x-六分之派)T=派
(1)a*b=0sin2x-cos2x=0sqr(2)sin(2x-π/4)=0x=π/8+kπ/2,k∈Z(2)f(x)=sqr(2)sin(2x-π/4)x∈(3π/8+kπ,7π/8+kπ),k
y=√3cosx+sinx=2[(√3/2)cosx+(1/2)sinx]=2(sinπ/3cosx+cosπ/3sinx)=2sin(x+π/3)所以它的最小正周期=2π;图像的对称轴为:x=kπ+
不用画图值域就是[-2,2]因为y=cosx的值域是[-1,1]
因为3sinx-2cosx=0,所以sinx/2=cosx/3.令sinx=2k,cosx=3k,k≠0.(1)原式=(3k-2k)/(3k+2k)+(3k+2k)/(3k-2k)=(1/5)+5=2
Y=sinx*cosx*√3+cos^2x=√3/2*sin2x+1/2*cos2x+1/2=sin(2x+∏/6)+1/2.
不管怎么写,都是有意义的.它只是函数,不存在成立不成立的问题.
没错,f(x)=2sin(2x+π/6)周期T=2π/2=π因为-1≤sin(2x+π/6)≤1f(x)max=2f(x)min=-2