Simplifying trig expresson

[Unregistered]

Simplify 1/√(x - a) when x=a cosec θ

How do you do this? Anyone please.

[MeatLoafRocks]

Sub x=a cosec θ into 1/√(x - a)

1/√(x - a) = 1/√(a cosec θ - a) = 1/√a( cosec θ - 1)

=1/√a( cot θ) from the identity cosec θ = 1 + cotθ

=1/a cotθ

=tan θ / a