
cosec(cos^1 (1/y)
Can someone please check this for me thanks.
Question is $\displaystyle \cos ec(\cos ^{  1} (\frac{1}{y})) = $
This is what I worked it to be
$\displaystyle
\begin{array}{l}
{\rm let }\theta = \cos ^{  1} (\frac{1}{y}) \\
\cos \theta = \frac{1}{y} \\
\cos ^2 \theta + \sin ^2 \theta = 1 \\
(\frac{1}{y})^2 + \sin ^2 \theta = 1 \\
\sin ^2 \theta = 1  (\frac{1}{y})^2 \\
\sin \theta = \sqrt {1  \left( {\frac{1}{y}} \right)^2 } \\
\cos ec\theta = \frac{1}{{\sin \theta }} = \frac{1}{{\sqrt {1  \left( {\frac{1}{y}} \right)^2 } }} \\
\end{array}
$
Is it right?(Thinking)

I did it a similar way and got what you did in a different form:
http://i116.photobucket.com/albums/o...sproblem24.jpg
My working was virtually the same.

not sure how to get from what I go to what you have ie y/(y+1)(y1)
