Question 610319
You can use the Pythagorean Theorem to find "r", the hypotenuse:
{{{(-20)^2 + (-15)^2 = r^2}}}
{{{400 + 225 = r^2}}}
{{{625 = r^2}}}
{{{25 = r}}}
Note: The "r" is always positive so we discard/ignore the negative square root.<br>
Now we can find the Trig function values:
{{{sin(theta) = y/r = (-15)/25 = (-3)/5}}}
{{{cos(theta) = x/r = (-20)/25 = (-4)/5}}}
{{{tan(theta) = y/x = (-15)/(-20) = 3/4}}}
{{{csc(theta) = r/y = 25/(-15) = 5/(-3)}}}
{{{sec(theta) = r/x = 25/(-20) = 5/(-4)}}}
{{{cot(theta) = x/y = (-20)/(-15) = 4/3}}}