True or False!!! :)

#1: sin(-x) = -cos x for all values of x.

***my answer; FALSE

is that right? @terenzreignz :)

Question

True or False!!! :)

#1: sin(-x) = -cos x for all values of x.

***my answer; FALSE

is that right? @terenzreignz :)

anonymous · Answer

#2:  also true or false! :)

sin(a+b) = sin a cos b - cos a sin b for all values of a and b.

***my answer: FALSE

is that right? :)

terenzreignz · Answer

First off, nice new colour :D
Now... let's see...

anonymous · Answer

color? :/ haha :/ lol confusion!

terenzreignz · Answer

Correct on both questions.

anonymous · Answer

yayyy!! :) thx!!! :D

terenzreignz · Answer

For future reference

sin(-x) = -sin(x)
NOT
-cos(x)

And 
sin(a+b) = sin(a)cos(b) + cos(a)sin(b)
NOT
sin(a)cos(b) - cos(a)sin(b)

anonymous · Answer

ahhh okay :) i see!! i'll keep that in mind!! Thanks!!! :D