Why...
cos (-125) = negative
cos (125) = still negative
2006-12-06 18:12:57 · 6 answers · asked by Help 1 in Science & Mathematics ➔ Mathematics
cos(x) = cos(-x) Since the Cosine wave is symmetrical about the y-axis.
2006-12-07 02:48:43 · answer #1 · answered by ludacrusher 4 · 1⤊ 0⤋
Result- cos (125) = double negative
2006-12-07 02:15:58 · answer #2 · answered by Anonymous · 0⤊ 0⤋
125 degrees is in the 2nd quadrant, where cosine is negative.
-125 degrees is in the 3rd quadrant, where cosine is also negative.
But it turns out that cosine is what is called an "even function": f(x) = f(-x).
cos x = cos -x
for all x.
Kenshin liked my answer so much that he copied it. Bad Kenshin!
2006-12-07 02:15:17 · answer #3 · answered by Jim Burnell 6 · 0⤊ 0⤋
cos x = cos (-x) and positive only when x is in 1st & 4th quadrant
2006-12-07 03:09:46 · answer #4 · answered by pksk212 3 · 0⤊ 0⤋
cos x = cos -x (that is the reason)
2006-12-07 02:21:55 · answer #5 · answered by Rim 6 · 0⤊ 0⤋
eaasy 2 say why, have U asked yourself WHY NOT !!!
2006-12-07 02:16:15 · answer #6 · answered by Anonymous · 0⤊ 0⤋