Within the same question as I previously posted about,
there is a jump not explaining conclusions that I can't quite see how the derivation was made.
cos cubed 2theta = (1 - sin squared 2theta)cos 2theta
Can anyone help?
Thanks
Within the same question as I previously posted about,
there is a jump not explaining conclusions that I can't quite see how the derivation was made.
cos cubed 2theta = (1 - sin squared 2theta)cos 2theta
Can anyone help?
Thanks
So, you know that $\displaystyle \cos^{2}(\theta)+\sin^{2}(\theta)=1$, I'm sure. What is $\displaystyle \cos^{2}(x)+\sin^{2}(x)$? How about $\displaystyle \cos^{2}(y)+\sin^{2}(y)$? And finally, my favorite, how about
$\displaystyle \cos^{2}(\text{stickfigure})+\sin^{2}(\text{stickf igure})$?
If all those are equal to the same thing, then you can see that no matter what you put inside the parentheses, you'll get one. So you could put in, say, $\displaystyle 2\theta$.