More Why you Suck at Math
This dumbassed video comes from CensorTube, from a channel calling itself "Higher Math": Everything is possible in math. Here, this dipshit wastes over 11 minutes solving this problem in the most convoluted manner possible.
x4= -4
It really is a simple problem. We have a degree 4 polynomial, so four roots to extract.
Step 1) Write it in Steinmetz form: x4= 4/_180 + 360n
x4= 4/_180(1+2n)
Step 2) Extract the roots:
x= 40.25/_45(1 + 2n) { n= 0, 1, 2, 3 }
X1= sqrt(2)/_45°
x2= sqrt(2)/_135°
x3= sqrt(2)/_225°
x4= sqrt(2)/_315°
You can leave it in that form, or if you prefer the Cartesian version, deriving it is easy peasy since sin(45)= cos(45)= 1/sqrt(2) Multiplying through:
x1= 1 + j
x2= 1 - j
x3= -1 + j
x4= -1 - j
Doing shit like this doesn't help, and it's obvious they aren't interested in teaching students the proper way, but to confuse and obfuscate. Is it any wonder why public gov't schools are failing, and why kids are getting more and more dumbed down?