At each of the points (7,7,(\pi )/(2)),((\pi )/(2),(\pi )/(2),\pi ),(-9,9,(5\pi )/(6)), evaluate the function w(r,s,t)=(r-s)/(sin(t)) or indicate that the function is
undefined there.
(Use symbolic notation and fractions where needed. If the function is undefined at the given point, type UNDEFINED.)
w(7,7,(\pi )/(2))=â—»
w((\pi )/(2),(\pi )/(2),\pi )=
w(-9,9,(5\pi )/(6))