Simplifying Trigonometric Expressions Using Identities, Example 1

[wrenkenstein]

I learned more in one minute than in a week of class. Hats off to you good sir.

[riskyvalera]

I always go to your channel when I have trouble with my homework, and you explain everything so well. You're an absolute life saver. Thank you so much!

[RodmanShah]

One of the most life saving videos on YouTube

[tentonk]

Omg. That's it?? So simple, I thought this was going to be harder than I thought. LOL. Love your videos man.

[sety]

Wow it doesn't seem easy but that made it look really easy

[anak]

I always come to your videos for help! THANK YOU!

[SCREAMOpants]

You make this easy to understand... thank you

[TheEnriquification]

You're like my go-to math teacher when 2nd period is over.

[boeingamerican]

did you go to MIT ? .... best explanation i ever saw.. great job!!

[chatblac]

It would be 1.
Negativity has no effect on cos or cos-based functions (meaning sec) (you can prove this by putting it on a circle, but it's basically because quadrant IV is positive for cos). So it = cos^2x(sec^2x). Which is cos^2x(1/cos^2x). Which is cos^2x/cos^2x therefore 1.

[patrickjmt]

@aljoshabre ha, i will probably post some more later... too lazy now : )

[TheZackBriggs]

@JoeSwagon I don't know now, that was a long time ago. I'm done with that class and passed. Thanks for acknowledding my question though. lol...

[patrickjmt]

i can splice in some techno music if you like

[TheZackBriggs]

How do i do cosx + sinx tanx
Im guessing you make tanx into sinx/cosx then multiply sinx/cosx times sinx/1 which would leave 1 times cosx. I now am left with cosx + cosx. I dont know what to do or know if I even did this right. Help please!

[jasminecc]

how do you know WHEN to use trig identities to substitute?

[MsVictoriousrocks]

This actually helps me . With the help of the magic hexagon . (if you know what i mean)

[coolio]

why can't we stop at (1/cosx)^3? (just curious) :D

[wiglumusic]

but i thought that opening parenthesis you must multiply sin over cos 3 times, i dont think u can just make it sinx to the power of three and cos x to the power of three, pls explain if u read

[ashleyenriquez]

I understand @_@ what kind of black magic is this ! I knew nothing before this :D thanks!

[yousiffanous]

How is tan equal to sin/cos. Isnt tan just opp/adj?