Answer
(a) $\frac{4}{5}$
(b) $-\frac{3}{5}$
(c) $-\frac{4}{3}$
(d) $-\frac{5}{3}$
Work Step by Step
Since point $P$ is in Quadrant II and on a unit circle with $y=4/5$,
we have $x=-\sqrt {1-(4/5)^2}=-3/5$. Use definitions of the trig functions:
(a) sin t =y=4/5
(b) cos t = x =-3/5
(c) tan t = y/x = -4/3
(d) sec t =1/x= -5/3
