# Addition of sin and cos

1. Mar 30, 2007

### Ry122

does cos + sin = 0?

2. Mar 30, 2007

### neutrino

cos + sin can never be equal to anything other than cos + sin. sin and cos are just functions. Neither has a "value" as such.

Do you want to if sin(somevalue1) + cos(somevalue2) = 0?

3. Mar 30, 2007

### sutupidmath

like neutrino said cos + sin have no meaning. But if we get let's say

sin(2n pi)+ cos[(pi/2)+n pi] =0, and there are more samples like this. if this is what you meant at first place?????

4. Mar 30, 2007

### f(x)

did you mean $$cosx+sinx=0$$ ?
$$\mbox{for the above to be true},\\ cosx=-sinx \\ \Rightarrow cotx=-1$$ (or $$sinx=0$$ but this does not hold for that.)

5. Mar 30, 2007

### ChaoticLlama

Please only post calculus questions in this forum.

6. Mar 30, 2007

### f(x)

LOL,this may well be calculus.....
$$Max(sinx+cosx)= \sqrt{2}$$
$$Min(sinx+cosx)= -\sqrt{2}$$
Since they function is continuous, it must have x such that f(x)=0

7. Mar 30, 2007

### Gib Z

$$\cos^2 x + \sin^2 x = 1$$