<p>Hello</p>
<p>If you know csc @= 3pi/2
How can you calculate @ in degrees</p>
<p>and</p>
<p>If you know csc 3pi/2=?
How can you calculate ??</p>
<p>for the first question @=arccsc 3pi/2-the inverse trigonometric function and you can find @ easily using a scientific calculator.
for the second question since 3pi/2 is an angle you can substitute it with 270° it's equivalent.
then csc 3pi/2= csc 270= 1/sin 270= -1/sin 90= -1</p>
<p>How would you type the first one in you scientific calc for example ti-83???</p>
<p>csc @= 3pi/2</p>
<p>for ti-83 you must do 1/sin @ = 3pi/2
for ti-89 titanium you can type in csc @ = 3p/2 directly.
*note, you cannot do this for ti-89 regular</p>
<p>Thanks merudh</p>
<p>I have one more question. If you own the barrons book, could you check for me if the answer of example 4 on page 60 is correct?</p>
<p>sorry man...don't got barrons but what's the question (I'm assuming this is for IIC or IC right?)</p>
<p>Ok I try to write it down</p>
<p>what is the answer:</p>
<p>sin [2 arctan (- 8/15)]</p>
<p>you need a decimal answer right?</p>
<p>if that's it then the answer is -.8304</p>
<p>are you sure it's negative???</p>
<p>Although I get the same answer as you, barrons says that it's positive....
I think it's a typo</p>
<p>yeah it has to be negative unless its written wrong. But then again, why would the arc tan it self be negative unless its just a straightforward problem. If the problem was for an actual triangle, you can't have an arctan with a negative number inside. know what i mean?</p>
<p>you mean that the angle never can be negative in an actual triangle??</p>
<p>well not in those triangle picture problems, but if you had like an triangle on a coordinate plane...yeah it can be.</p>
<p>anyway yeah I test it out...there is no way the answer can be positive unless the value is the arctan is positive. For the answer to be .830 then the value has to be either 15/8 or 8/15.</p>