Since the order of the students selected is important in this item, the concept used for this question is that of the permutation. For this item it is the "permutation of 28 taken 6". This may be mathematically expressed as 28P6. The numerical answer is 271252800. Thus, the answer is letter C.
The graph is a circle, centered at the origin, with radius=4.
We know that we can write the equation of a circle with radius r and center (a,b) as :
![(x-a)^2+(y-b)^2=r^2](https://tex.z-dn.net/?f=%28x-a%29%5E2%2B%28y-b%29%5E2%3Dr%5E2)
.
Thus, substituting (a, b) with (0, 0) and r with 4, we have:
![x^2+y^2=16](https://tex.z-dn.net/?f=x%5E2%2By%5E2%3D16)
.
The solutions of this equation are all the points forming the circle shown in the picture. The solutions of this equation are still the same even if we multiply both sides of the equation by 2, because rewriting the equation as:
![x^2+y^2=16\\\\x^2+y^2-16=0\\\\2(x^2+y^2-16)=0](https://tex.z-dn.net/?f=x%5E2%2By%5E2%3D16%5C%5C%5C%5Cx%5E2%2By%5E2-16%3D0%5C%5C%5C%5C2%28x%5E2%2By%5E2-16%29%3D0)
,
we would still have the same roots.
Thus, the equation of the circle can be written as :
![2x^2+2y^2=32](https://tex.z-dn.net/?f=2x%5E2%2B2y%5E2%3D32)
.
Answer: B
Answer:
Step-by-step explanation:
Answer:
5sqrt3
Step-by-step explanation:
Using the pythagorean theorem, we have a^2+4^2=9^2
a^2 + 16 = 81
a^2 = 75.
a = sqrt75.
75 = 25*3. 25 is a perfect square, so sqrt75 = 5sqrt3
The answer is option c. Thank you