Thread: Sine and Cosine

Not sure what this question is asking me, when their is no numbers to calculate, can someone please explain this to me

If Cos(x)=m then what is the value of Cos (180-x)?

Thanks

It's a trigonometric identity.

cos(180 - x) is always the opposite of cos(x).

You could come to that conclusion several ways, but the easiest method is to look at a typical angle Q on a graph and compare it with its supplement (which is defined as 180 - Q), and then you will see why the conclusion is true.

Originally Posted by icemanfan

It's a trigonometric identity.

cos(180 - x) is always the opposite of cos(x).

You could come to that conclusion several ways, but the easiest method is to look at a typical angle Q on a graph and compare it with its supplement (which is defined as 180 - Q), and then you will see why the conclusion is true.

so the answer that i would be looking for then is -cos(180-x), or am i way out to lunch on this one

Originally Posted by nuckers

so the answer that i would be looking for then is -cos(180-x), or am i way out to lunch on this one

Well, if cos(x) = m and cos(180 - x) is the opposite of cos(x), then what does cos(180 - x) equal in terms of m?

Originally Posted by nuckers

so the answer that i would be looking for then is -cos(180-x), or am i way out to lunch on this one

if , then

... that's all.

Originally Posted by icemanfan

Well, if cos(x) = m and cos(180 - x) is the opposite of cos(x), then what does cos(180 - x) equal in terms of m?

Ok, i understand now, thanks so much for the help