Trig Expression

[new_slang]

Hi there!

Need some help with this one question from Trigonometry. It's an identity of sorts.

I need to prove that sinx + cos^2x cscx is equal to cscx.

Thank you!

 

[tkhunny]

Use Crutch #2 - When in doubt, change everything to equivalent sines and cosines and see what developes.

 

[new_slang]

Okay, thank you.

Now I'm curious to what Crutch #1 is

To anyone who is wondering how I solved it.

replace cscx with 1/sinx
sinx + cos^2(x) (1/sinx)
sinx + (cos^2(x)/sinx)
replace cos^2(x) with (1-sin^2(x)
sinx + (1 - sin^2(x)/sinx)
get common denominator of sinx
1/sinx
csc

 

[tkhunny]

Only #2 is a "crutch".

Method #1 is "Do Something"! You stare at those identities for a reason.

 

[mmm4444bot]

I'm curious to what Crutch #1 is

Posting a request for help on the Internet. :wink:

 

[tkhunny]

That's not very nice. You meet so many nice people out here!