00:01
Okay, so we're starting with 1 minus root 5 to the 8th power.
00:07
And we want to leave this in a plus bi form, but i find the easiest way to get there is to work in polar forms.
00:13
The first thing i'm going to do is take a quick sketch of this.
00:15
This is going to end up being a point in the fourth quadrant, one unit to the right, root five units down.
00:24
When i use pythagorean theorem, i have one squared plus root five squared, take the square root, which is going to come out to be root 6.
00:34
So so far we have root 6, and then we have to find our angle.
00:38
So i'm going to take the inverse tangent of opposite, which is root 5 over 1.
00:46
Now notice i left it positive because we're looking for a reference angle.
00:49
The reference angle here is going to come out to be 65 .91 degrees.
00:59
But it's in the fourth quadrant, so we take 360 and subtract 65 .0 .2.
01:05
And we're going to end up with 294 .09.
01:10
So right now we've got root 6, sys 294 .09.
01:18
And again, for those that don't remember, cis is cosine plus i sign...