If and where does this happen?
2007-02-02 09:12:03 · 6 answers · asked by ? 2 in Science & Mathematics ➔ Mathematics
when sin(x) = -cos(x)
which is in the second and fourth quadrants at a 45deg angle or
deg 135 or 315.
2007-02-02 09:24:58 · answer #1 · answered by borgerm 2 · 1⤊ 3⤋
1+1=0
2015-07-25 02:03:06 · answer #2 · answered by Nam 1 · 0⤊ 2⤋
It happens where they cross each other.
sinx = -cosx
==> sinx/cosx = 0
The only place this can occur is when sinx = 0......right??
When does sinx = 0?
...at multiples of π.
So, the complete solution woudl be nπ where 'n' = є {0, 1, 2...}
This means that 'n' is in the set of all n with the values shown.
Make sense?
2007-02-02 09:30:42 · answer #3 · answered by Anonymous · 0⤊ 4⤋
sinx = -cosx
cos(pi/2 - x + 2n pi) = cos(pi + x)
pi/2 - x + 2n pi = pi + x
Therefore, we have the general solution:
x = -pi/4+n pi, where n can be any integer.
In [0, 2pi), pick n = 1, and 2
x = (3/4)pi, and x = (7/4)pi, respectively.
2007-02-02 10:36:19 · answer #4 · answered by sahsjing 7 · 3⤊ 1⤋
It occurs where the sin and cos have equal but opposite values.
like at 135 degrees and 315 degrees
2007-02-02 10:19:43 · answer #5 · answered by davidosterberg1 6 · 2⤊ 2⤋
dividing by cos x you get tgx +1 = 0===> tg x = -1 which yields
x= 3pi/4 and x= 7pi/4 in the interval (0,2pi)
2007-02-02 09:22:52 · answer #6 · answered by santmann2002 7 · 1⤊ 3⤋