Question 495691: Find the exact value without a calculator:
cot(7pi/2)
Answer by lwsshak3(11628)   (Show Source):
You can put this solution on YOUR website! Find the exact value without a calculator:
cot(7pi/2)
**
There are different ways you can visualize doing this on a unit circle:
..
π/2=90º
7π/2=7*90=630º
Rotating one revolution counter clockwise from zero, covers 360º. which means you have 270º left (630-360=270). Sin 270º=-1, and Cos 270º=0
Cot=cos/sin
Cot(7π/2)=0/-1=0
..
7π/2=(3-1/2)π, which means you can visualize rotating thru π radians 3 times leaving π/2 left over which ends on 3π/2, where Cot=0. Similarly, you can visualize rotating 7 times thru π/2 which will also end on 3π/2.
|
|
|
