(1+cscθ)(1-sinθ)=(1+1/sinθ)(1-sinθ)=1-sinθ+1/sinθ-1
=1/sinθ-sinθ=(1-sin²θ)/sinθ=cos²θ/sinθ
=cotθcosθ
证明（1+cscθ）（1-sinθ)=cotθcosθ
1个回答
相关问题
-
怎么知道cotθ/cscθ=(cosθ/sinθ)/(1/sinθ).怎么样一看就知道cotθ/cscθ=(cosθ/s
-
证明cotθ+cscθ=cot(θ/2)
-
若f(θ)=sinθ/(|sinθ|)+cos(θ)/|cosθ|+tanθ/|tanθ|+cotθ/|cotθ|,求y
-
若θ为第二象限角,则sinθ/|sinθ|+√1-sin^2θ/|cosθ|+tanθ/|tanθ|+cotθ/|cot
-
求证:sin^2θtanθ+cos^2θcotθ+2sinθcosθ=tanθ+cotθ
-
化简sinθ(1+tanθ)+cosθ(1+cotθ)
-
tan²θ+cot²θ-sin²θtan²θ-cos²θcot&sup
-
化简sin(θ-π)cos(θ-3/2π)cot(-θ-π)/tan(θ+3π)sec(-θ-2π)csc(π/2-θ)
-
sin^2θ/sinθ-cosθ + cosθ/1-tanθ = sin^2θ/sinθ-cosθ + cosθ/1-(
-
求证 【sinθ(1+sinθ)+cosθ(1+cosθ)】×【sinθ(1-sinθ)+cosθ(1-cosθ)】=s