Question

cos(-x)=-cosx for all values of x.

True or False?

Answer 1

Nevermind, I figured out it was false!

Answer 2

false

Answer 3

cos (a-b) = cos a*cos b + sin a*sin b. Let a = 0 and b = x.

Answer 4

it is false because cos x is a even function and even function are characterised as f(-x)=f(x). In reference to this I would like to state what an odd function is, those function in which a negative value of the domain yields a negative sign in the range ex:
f(x)=sinx
lets take x=-x we have
we have f(-x)=sin(-x)=- sin x =-f(x)

in odd function f(-x)=-f(x)

Answer 5

http://www.mathsisfun.com/algebra/functions-odd-even.html

Answer 6

Yes, I figured that out x) Thank you for explaining though!

Answer 7

Please check the link. You will have a clear idea and never forget it again. I too use to make a lost of mistake with the odd and even functions. :)

Your Welcome.