Submit the correct question, In first bracket / will be there so

((1/(secA.secA-cosA.cosA))-(1/(cosecA.cosecA-sinA.sinA))).sinA.sinA.cosA.cosA

= [cos²A/sin²A(1+cos²A) - sin²A/cos²A(1+sin²A)]sin²Acos²A

= [cos⁴A(1+sin²A) - sin⁴A(1+cos²A)] / [(1+sin²A)(1+cos²A)]

now solve