y=sin^2x-3sinxcosx+4cos^2x是否等于y=sin^2x+cos^2x+3cos^2x-3/2*sin2x?y=sin^2x-3sinxcosx+4cos^2xy=sin^2x+cos^2x+3cos^2x-3/2*sin2x=1+3cos^2x-3/2*sin2x=1+3（1-sin^2x）-3/2*sin2x=-3sin^2x-3/2*sin2x+4

函数y=sinxcosx-3sin^2(x)的最大值 y=sin^4x+2√3 sinxcosx-cos^4x 化简 y=sin^4x+2根号3sinxcosx-cos^4 化为同名函数 y=(cos^2x)/(sinxcosx-sin^2x),(0 求y=sin^2x+2sinxcosx的周期 y=sin^2x+2sinxcosx的值域 y=sin^2x-sinxcosx+1/2的值域 求y=sin^2(x)-sinxcosx+2的值域 求y=sin平方x+2sinxcosx的周期 求y=sinxcosx+sin^2x,0 y=cos^x-4根号3sinxcosx-3sin^x的最大值在【0,pi/2】的条件下 y=2sin^2 x+4sinxcosx+5cos^2 x 化简 y=1/2cos^2x+sinxcosx+3/2sin^2x 求单调区间 化简：y=cos^4 x＋2 sinxcosx－sin^4 x 求函数y=7-8sinxcosx+4cos^2x-4sin^x的最小值 y=2sin^2x-sinxcosx+3cos^2x 求值域 y=sin'2x+根号3sinxcosx+2cos'2x求值域和周期 y=sin^2x+2sinxcosx+3cos^2x的值域?