Question

Trig help?

Answer 1

In the answer for #2, can someone please explain how the a just disappears?

Answer 2

It goes from cos(pi/2 - (a + b))
To cos(pi/2 - b)

Where did the a go?

Answer 3

Typo, sloppy sloppy!
They meant to write this:\[\large\rm \sin(a+b)=\cos\left(\left[\frac{\pi}{2}-a\right]-b\right)\]And then hopefully you can see that this makes sense when they apply the Sine Angle Difference Formula in the next step, ya?

Answer 4

This course is getting on my nerves with these typos -_-
I get hung up on problems like these, wondering if I've gone blind or what.
Yes, I can figure it out from here. Thanks for confirming my suspicion that it was a slip up. I don't get how no one catches the typos in the course!

Answer 5

:P

Answer 6

If there is any type of communication system on the site,
you should try to let them know about the errors that you find,
so others students don't continue to scratch their heads and fumble around in the black of night t.t with pi on their brains.

Answer 7

I've been letting my teacher know. But seriously... this same course has been around for years now. You'd think someone would have caught all of these mistakes. -_-
Anyway... off to do more math

Answer 8

dsa

Answer 9

hmmm?