## StokesParadox one year ago @zepdrix

1. zepdrix

Hmm darn, I have plenty of resources for Calculus... I can't think of any for trig though haha.

I'm looking at yesterdays problems...one seconds.... we should probably start with inverses of trig functions..one second

do these look difficult enough (for me)

5. zepdrix

Hmm they look pretty simple. I wouldn't say they're way easier than what we were working on yesterday. They might be worth spending some time on c:

6. zepdrix

Take a stab at #3

yeah they look too easy....I'll find some harder ones $sin(5x)=-\frac{\sqrt 3}{2}$ |dw:1362793858479:dw| am I right so far?

8. zepdrix

Solve for x! :)

9. zepdrix

I mean, yes you're right so far!

10. zepdrix

Keep in mind we want to rotate in the positive direction. So make sure your angle corresponds to that.

$sin^{-1}(-\sqrt{3}/2)=5x$ uhm I'm stuck $\frac {5\pi} 3$

12. zepdrix

$\large 5\pi/3=5x$ So you found that your angle, $$\large 5x$$ was equal to the special angle $$\large 5\pi/3$$. Looks good so far.

oh so that is right!

$x=\frac {\pi}{3}$

15. zepdrix

Yay good job

wait, that's it? what did we just discover?

wait wait wait....

18. zepdrix

There is some angle $$\large 5x$$ that corresponded to the given equation. And we were ultimately trying to find 1/5 of that angle. No waiting! >:O lol

LOL $sin(5x)=-\frac{\sqrt 3}{2}$ why are we trying to find 1/5 of that angle do you mean: "there is some angle x"

20. zepdrix

Our angle is the thing inside of the trig function. Think of it maybe as like, $$\large 5x=\theta$$. We want to solve for part of that angle. But for the purposes of relating this to special angles, it's good to think of the entire contents as the angle. :)

I am.....so why are we trying to find 1/5 of that angle? Oh you're just saying we solve for x which is 1/5th of that angle....I think I get it

si?

23. zepdrix

si c: I'm just being a little technical I guess.

It makes sense :)

should we do a more difficult problem? what are these problems called $sec\left(cos^{-1}\frac 12\right)$ I feel sooooo d u m b LOL

26. zepdrix

lol poor gal c:

27. zepdrix

Ok so we're dealing with an inverse even function on the inside. So our angle will be in the 1st or second quadrant, yes? Hmmm +1/2. Is that a length to the right, or left? :D

I will feel smarter by the end of the weekend....hopefully.... When I Know How To Do These Darn Problems o.O

right

the length to the right

I found some nice aerobics music!!!!

32. zepdrix

lol that was random XD

Thanks :)

I'm planning to work out in 15 mins

36. zepdrix

Oh i see c:

....so these problems are called inverse functions within trig functions? i"m trying to find some problems on google.

38. zepdrix

Sorry I'm not quite sure what they're called :( Maybe something Composition of Trig functions...

39. zepdrix

http://www.ck12.org/book/CK-12-Trigonometry-Concepts/r1/section/4.6/ Near the bottom there is a $$\large \text{Practice}$$ section. Some good problems there.

which one should a take a stab at?

42. zepdrix

5

$tan(cos^{-1}1)$ $cos\alpha =1$ at zero and $$2\pi$$

44. zepdrix

$\large \tan(0)$ K looks good so far.

46. zepdrix

Yes good!