Answer:
The easiest way is to round down to 40 and take 50% of that, which is 20. The actual answer is 20.5.
Step-by-step explanation:
ANSWER

EXPLANATION
The given angle is 870°.
870°-360°-360°=150°
This means that:
870° is coterminal with 150°, hence its terminal side is in the second quadrant.
It makes an acute angle of 30° with the x-axis.
Note that cotangent is negative in the second quadrant,
Hence,

The first option is correct.
Answer:
x= -40
Step-by-step explanation:
Cost
C(x)=1,600+20x
P(x)=100-x
Revenue=x*p(x)
=x*(100-x)
=100x-x^2
Cost=Revenue
1600+20x=100x-x^2
1600+20x-100x+x^2=0
1600-80x+x^2=0
Solve using quadratic formula
Formula where
a = 1, b = 80, and c = 1600
x=−b±√b2−4ac/2a
x=−80±√80^2−4(1)(1600) / 2(1)
x=−80±√6400−6400 / 2
x=−80±√0 / 2
The discriminant b^2−4ac=0
so, there is one real root.
x= −80/2
x= -40
2cosx=2sin2x. Sin2x is an identity for 2sinxcos. So 2[2sinxcosx] gives you 4sinxcosx. 2cosx=4sinxcosx. Divide 2cosx on both sides and gives you 2sinx=0 and divide again, sinx=0. Sinx is 0 at 0 and 360 degrees, or pi and 2pi. So thats what x would be. 0,360,pi,2pi.
Answer
5/22 (fun fact that is my birthday)
Step-by-step explanation:
9/11 * 5/18=45/198=5/22