intrigation

i think it will be of no use ,i tried with cos2x as 2cox²x -1,the cosx in the dinominator is creating the problem

seeing it carefully u ll observe the given q is same as sec²x.dx/√1-tan²x.i hope this ll solve our problem

multiply numerator n denominator by sec x...n write denominator in terms of tan x..n take tan x=z...den do substitution..