f(x)=cos2x/sin(x+π/4) 若f(x)=4/3,求sin2x的值

来源：学生作业帮编辑：作业帮分类：数学作业时间：2024/05/20 10:19:13

cos2x/sin(x+π/4) =4/3
cos2x/sin(x+π/4) =4/3
(cos² x-sin² x)/sin(x+π/4) =4/3
(cosx-sinx)(cosx+sinx)/sin(x+π/4) =4/3
(cosx-sinx)[√2(√2/2cosx+√2/2sinx)]/sin(x+π/4) =4/3
(cosx-sinx)[√2(sinπ/4cosx+cosπ/4sinx)]/sin(x+π/4) =4/3
(cosx-sinx)[√2sin(x+π/4)]/sin(x+π/4) =4/3
√2(cosx-sinx)=4/3(平方）
2(cosx-sinx)²=16/9
(cosx-sinx)²=8/9
cos²x+sin²x-2sinxcosx=8/9
1-2sinxcosx=8/9
2sinxcosx=1/9
sin2x=1/9

已知函数f(x)=cos2x\ sin(x+π\4) 若f(x)= 4\3 ,求sin2x的值已知函数f(x)=cos2x/sin(x+π/4）,求函数f(x)的定义域求：若f(x)=4/3,sin2x的值已知函数f(x)=cos2x\ sin(x+π\4),求函数f(x)的定义域已知函数f(x)=sin2x+cos2x,若f(A)=3/4,求sin4x 函数f(x)=sin2x+根号3cos2x,求f(x)的周期和值域上单调递增,求w的取值范围已知函数f(x)=2cosx X sin(派/2+x)+sin2x-cos2x ①求f(派/8 已知f(x)=sin^2x+sinxcosx.x属于(0,派/2),若f(x)=3/4,求sin2x的值已知函数f(x)=cos2x/[sin(π/4-x)] f（X）=Cos2X-Sin2X,求f（0.45）已知函数f(x)=2cos2x+sin^2x-4cosx.制值 (1)求f(π/3)的值 (2)求f 设向量a=(根号3sin2x,cos2x),b=(sin2x,sin2x),若函数f(x)=ab+t求函数f(x)的最小设向量a=(根号3sin2x,cos2x),b=(sin2x,sin2x),若函数f(x)=ab+t,求函数f(x)的最