<p>whats cis??? I've never heard of that before....</p>
<p>In order to study for the Math II c test, im buying the Kaplan and Barrons book. is there any other book I should buy? </p>
<p>thanks</p>
<p>cis is just another expression of describing coordinates..i think..
for instance 4cis45 = 4cos45 + 4i sin45 (*note that "i" indicates y-coordinate) This means that it's showing the coordinate
( 4cos45, 4sin45)</p>
<p>say you have a rectangular coordinate of (a,b), and you wanna change it to polar coordinate. You should know then the polar form is like
(magnitude, degree). In this case, it would be (squre root of (a^2+b^2), and inverse tan of b/a)</p>
<p>if you understand what i just explained above, i think you're fine.</p>
<p>i didnt understand that ... I guess maybe thats cause I havent done precalculus...</p>