Graph of Cardioid Solution with Cosine Calculation

[bobsmith76]

Homework Statement

The Attempt at a Solution

I don't see how they get

1 - cos (pi/3) = 1/2

cos (pi/3) = √3/2

1 - √3/2 = .14, not .5 like the book says

for the other figures I agree with the book.

 

[Mark44]

Homework Statement

The Attempt at a Solution

I don't see how they get

1 - cos (pi/3) = 1/2

What's not to get? cos($\pi$/3) = 1/2.

You need to brush up on your trig.

cos (pi/3) = √3/2

No, this is not true. sin($\pi$/3) = √3/2.

1 - √3/2 = .14, not .5 like the book says

for the other figures I agree with the book.

 

[bobsmith76]

never mind, I was mixing pi/6 up with pi/3