Question 1031224
.
Given that cos t = 8/9 and that P(t) is a point in the fourth quadrant, find sin t.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


<pre>
Since cos(t) = {{{8/9}}}, you have 

{{{sin^2(t)}}} = {{{1 - cos^2(t)}}} = {{{1 - (8/9)^2) = {{{1 - 64/81}}} = {{{81-64)/81}}} = {{{17/81}}}.

Hence, sin(t) = +/- {{{sqrt(17)/9}}}.

Now, what sign,  "+"  or  "-",  to choose? 

Since P(T) is in QIV, what sign for sin(t) will you choose? 
</pre>

<U>Comment from student</U>: Thanks so much for the help! By the way, I'm thinking that the sign would be negative?


<pre>
<U>My response</U>:  you are right!  Hope next time you will be able to solve similar problems on your own.  Good luck!!!
</pre>