<p>please help me with this question</p>
<p>Suppoise the terminal point (x, y) for an arclength t is on the unit circl in quadrant IV. Suppose x =9/10. Find the exact value of tan t. </p>
<p>I posted in AP forums but no one is answering. Help !!!!</p>
<p>(If I am reading your question correctly...)</p>
<p>x = 0.9; given
x squared + y squared = 1; since the point (x,y) lies on a unit circle
y = the squareroot of (1 - x squared);
y = -0.44; we know y is less than 0 due to 4th quadrant restriction
y/x = tan t
tan t = -0.48; substituting</p>
<p>An equivalent solution is</p>
<p>Tan(arcsin(x)) = 0.48 which becomes -0.48 in fourth quadrant.</p>
<p>thanks a lot. I was totally stumped</p>