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高一数学若f(x)满足2f(-sinx)3f(sinx)=4si?

2005-07-10 14:26:48好***
若f(x)满足2f(-sinx)+3f(sinx)=4sinxcosx(-90<=x<=90). “度”我就不写了高一数学若f(x)满足2f(-sinx)3f(sinx)=4sinxcosx(-90=x=90).求f(x)若f(x)满足2f(-sinx)+3?

最佳回答

  • x=sina=x1 2f(-x1)+3f(x1)=4x1(1-x1^2)^0.5 -x=-sina=x2 2f(-x2)+3f(x2)=4x2(1-x2^2)^0.5 so 2f(-x)+3f(x)=4x(1-x^2)^0.5 (1) 2f(x)+3f(-x)=-4x(1-x^2)^0.5 (2) (1)*3-(2)*2 5f(x)=20x(1-x^2)^0.5 f(x)=4x(1-x^2)^0.5
    2005-07-10 15:23:01
  • 2f(-sinx)+3f(sinx)=4sinxcosx(-90<=x<=90). sinx=t 2f(-t)+3f(t)=4tgenhao(1-tt) (1) 2f(t)+3f(-t)=-4tgenhao(1-tt) (2) 解得3(1)-2(2) 5f(t)=4tgenhao(1-tt) f(x)=4xgenhao(1-xx) /5 -1<=x<=1
    2005-07-10 16:04:32
  • 很赞哦! (226)