It could include all real numbers, really. If you have +$130 you could use them to pay for something. If you have -$27.5 you need to pay this sum to the bank, since you overused your credit.
<h3>
</h3>
Answer:
Solution given
Cos
consider Pythagorean theorem
Subtracting 
both side
doing square root on both side we get
Similarly
Substituting value of 
we get
<h3>Solving numerical</h3>
Since
In IVquadrant sin angle is negative
The answer is 43.96 2 time pi time the radius
6:3 = 6/3 = 2
13 to 4 = 13:4 = 13/4 = 3.25
19/2 = 9.5
15 to 10 = 15:10 = 15/10 = 1.5
8:2 = 8/2 = 4
From the least to the greatest:
15 to 10 , 6:3, 13 to 4, 19/2
I hope this explains it.
X=2 Y=-1 plug them into the equation
-3(2)^2 + 2(-1)^2 + 5(2)(-1) -2(-1) + 5(2)^2 -3(-1)^2
36+4-10+2+100+9
40-10+2+100+9
30+2+100+9
132+9
141
