how is (1 + cos 2theta)^2 = (1 + 2 cos 2theta + (1 + cos 4theta)/2) ?
K kulgamer New member Joined Feb 8, 2012 Messages 3 Feb 8, 2012 #1 how is (1 + cos 2theta)^2 = (1 + 2 cos 2theta + (1 + cos 4theta)/2) ?
pka Elite Member Joined Jan 29, 2005 Messages 11,990 Feb 8, 2012 #2 kulgamer said: how is (1 + cos 2theta)^2 = (1 + 2 cos 2theta + (1 + cos 4theta)/2) ? Click to expand... Hint: \(\displaystyle cos(4\theta)=2\cos^2(2\theta)-1\).
kulgamer said: how is (1 + cos 2theta)^2 = (1 + 2 cos 2theta + (1 + cos 4theta)/2) ? Click to expand... Hint: \(\displaystyle cos(4\theta)=2\cos^2(2\theta)-1\).
S srmichael Full Member Joined Oct 25, 2011 Messages 848 Feb 8, 2012 #3 kulgamer said: how is (1 + cos 2theta)^2 = (1 + 2 cos 2theta + (1 + cos 4theta)/2) ? Click to expand... Another hint: \(\displaystyle \displaystyle cos^2(\theta)=\frac{1+cos(2\theta)}{2}\)
kulgamer said: how is (1 + cos 2theta)^2 = (1 + 2 cos 2theta + (1 + cos 4theta)/2) ? Click to expand... Another hint: \(\displaystyle \displaystyle cos^2(\theta)=\frac{1+cos(2\theta)}{2}\)
