#csc t = 1/(sin t) = - 3/2# --> #sin t = - 2/3#
#sin t = - 2/3#
#cos^2 t = 1 - sin^2 t = 1 - 4/9 = 5/9# --> #cos t = +- sqrt5/3#
#cos t = - sqrt5/3# (cos t < 0)
#tan t = sin/(cos) = (- 2/3)(- 3/sqrt5) = 2/sqrt5 = (2sqrt5)/5#
#cot t = 1/(tan t) = 5/(2sqrt5)#.
#sec t = 1/(cos) = - 3/sqrt5 = - (3sqrt5)/5#.
#csc t = -3/2#