Science talk:Math Exam Resources/Courses/MATH102/December 2014/Question C 03

In a solution this long we need more hints. Perhaps some of the special triangles or something to help lead on the solution.

Also the work for $\phi$ should be shown and not just 'similarly'.

Lastly some note should be made that critical points also occur where the denominator is 0 (though in this case this is impossible).