To solve this problem you must apply the proccedure shown below: 1. You have: (secθ/cscθ-cotθ)-(secθ/cscθ+cotθ) 2.Substract both expressions, as following: secθcscθ+secθcotθ-secθcscθ+secθcotθ/(cscθ-cotθ)(cscθ+cotθ) 3. Simpliying: (2secθcotθ)/(cscθ-cotθ)(cscθ+cotθ) 4.Let's solve the numerator and then the denominator: The numerator: (2secθcotθ)=(2/cosθ)(cosθ/sinθ)=2cosθ/(cosθ)(sinθ)=2/sinθ The denominator: (cscθ-cotθ)(cscθ+cotθ)=(1/sinθ-cosθ/sinθ)(1/sinθ+cosθ/sinθ)=(1-cosθ/sinθ)(1+cosθ/sinθ)=1-cos^2θ/sin^2θ=sin^2θ/sin^2θ=1 5. Let's susbtitute the numerator and the denominator: (2/sinθ)/1=2/sinθ=2cscθ
