follows from the fact that the cosine function is
-periodic, which means
. Roughly speaking, this is the same as saying that a point on a circle is the same as the point you get by completing a full revolution around the circle (i.e. add
to the original point's angle with respect to the horizontal axis).
If you make another complete revolution (so we're effectively adding
) we get the same result:
. This is true for any number of complete revolutions, so that this pattern holds for any even multiple of
added to the argument. Therefore
for any integer
.
Next, because
, it follows that
is also true for any integer
. So we have
The rest follows from considering either case and solving for
.
Answer:
A
Step-by-step explanation:
9 > 3 + 2x
6 > 2x
3 > x
or
x < 3
and that means 3 is NOT included (otherwise there must be a smaller or equal sign). hence A is the right answer.
I think it’s the number 3 I’m not sure I’m learning this stuff rn I’m getting the hang of it just it’s hard and not hard at the same time
X cannot equal +2, and can't be -1. If you factor it, then you notice you get 2(x+2)(x-2). If you use either one for the x, one will be zero and the won't, and vise-versa.
Answer:
y=1.7
x=.9
Step-by-step explanation:
