I first tried to calculate(simplify)
-(Cosφ-Sinφ)^2-Sinφ+Cosφ^2--k^2Sin[Θ]Sin[φ]Cos[φ]/Sqrt[r^2-k^2Sin[φ]^2]^2
this in Wolfram|Alpha and the result was "Wolfram|Alpha doesn't understand your query". I thought it was because the expression was too long, so I moved to Mathematica and tried to compute
-(Cos[CurlyPhi]-Sin[CurlyPhi])^2-Sin[CurlyPhi]+Cos[CurlyPhi]^2--k^2Sin[[CapitalTheta]]Sin[[CurlyPhi]]Cos[[CurlyPhi]]/Sqrt[r^2-k^2Sin[[CurlyPhi]]^2]^2\Refine\Simplify
this. But it showed me a syntax error. Is there a way to fix this?
+This is my first time using Mathematica so it might be a stupid mistake.