the given expression is
Sinx/ cscx + cosx/secx = 1
we know that
cosec(x) = 1/ sin(x)
and
sec(x) = 1 /cos(x)
put the values,
[tex]\frac{\sin x}{\frac{1}{\sin(x)}}+\frac{cosx}{\frac{1}{\cos (x)}}=1[/tex][tex](\sin x)^2+(\cos x)^2=1[/tex]
thus, identity is
[tex]\sin ^2x+\cos ^2x=1[/tex]
