Thread: How Good Am I? View Single Post
HW Helper
P: 3,353
 Quote by murshid_islam you used the substitution $$x = \frac{1}{2}\tan\theta$$ from this, you get, $$\tan\theta = 2x$$ and from this, you get $$\theta = \arctan(2x)$$ and $$\sin\theta = \frac{2x}{\sqrt{4x^2+1}}$$ and $$\cos\theta = \frac{1}{\sqrt{4x^2+1}}$$. and you also know that $$\sin 2\theta = 2\sin\theta\cos\theta$$
Sorry, I'm afraid you may be a bit confused. I used the substitution x=1/2 tan theta on Hootenanys approach, When I get to where you were showing me, I was doing my own trigonometric substitution that was not x=1/2 tan theta. SOrry