Answer:
i think its 7
Step-by-step explanation:
28 miles per 4 hours, so you divide them both by 4 and get 28 divided 4
and 4 divided by 4. so its 7/1 which just equals 7. please correct me if im wrong good luck.
Answer:
![\large\boxed{A.\ (x+6)^2+(y+10)^2=20}](https://tex.z-dn.net/?f=%5Clarge%5Cboxed%7BA.%5C%20%28x%2B6%29%5E2%2B%28y%2B10%29%5E2%3D20%7D)
Step-by-step explanation:
The standard form of an equation of a circle:
![(x-h)^2+(y-k)^2=r^2](https://tex.z-dn.net/?f=%28x-h%29%5E2%2B%28y-k%29%5E2%3Dr%5E2)
(h, k) - center
r - radius
We have the endpoints of the diameter of a circle (-8, -6) and (-4, -14).
The midpoint of a diameter is a center of a circle.
The formula of a midpoint:
![\left(\dfrac{x_1+x_2}{2},\ \dfrac{y_1+y_2}{2}\right)](https://tex.z-dn.net/?f=%5Cleft%28%5Cdfrac%7Bx_1%2Bx_2%7D%7B2%7D%2C%5C%20%5Cdfrac%7By_1%2By_2%7D%7B2%7D%5Cright%29)
Substitute:
![x=\dfrac{-8+(-4)}{2}=\dfrac{-12}{2}=-6\\\\y=\dfrac{-6+(-14)}{2}=\dfrac{-20}{2}=-10](https://tex.z-dn.net/?f=x%3D%5Cdfrac%7B-8%2B%28-4%29%7D%7B2%7D%3D%5Cdfrac%7B-12%7D%7B2%7D%3D-6%5C%5C%5C%5Cy%3D%5Cdfrac%7B-6%2B%28-14%29%7D%7B2%7D%3D%5Cdfrac%7B-20%7D%7B2%7D%3D-10)
We have h = -6 and k = -10.
The radius is the distance between a center and the point on a circumference of a circle.
The formula of a distance between two points:
![d=\sqrt{(x_2-x_1)^2+(y_2-y_1)^2}](https://tex.z-dn.net/?f=d%3D%5Csqrt%7B%28x_2-x_1%29%5E2%2B%28y_2-y_1%29%5E2%7D)
Substitute (-6, -10) and (-8, -6):
![r=\sqrt{(-8-(-6))^2+(-6-(-10))^2}=\sqrt{(-2)^2+4^2}=\sqrt{4+16}=\sqrt{20}](https://tex.z-dn.net/?f=r%3D%5Csqrt%7B%28-8-%28-6%29%29%5E2%2B%28-6-%28-10%29%29%5E2%7D%3D%5Csqrt%7B%28-2%29%5E2%2B4%5E2%7D%3D%5Csqrt%7B4%2B16%7D%3D%5Csqrt%7B20%7D)
Finally we have
![(x-(-6))^2+(y-(-10))^2=(\sqrt{20})^2\\\\(x+6)^2+(y+10)^2=20](https://tex.z-dn.net/?f=%28x-%28-6%29%29%5E2%2B%28y-%28-10%29%29%5E2%3D%28%5Csqrt%7B20%7D%29%5E2%5C%5C%5C%5C%28x%2B6%29%5E2%2B%28y%2B10%29%5E2%3D20)
The axis of symmetry of a quadratic function
![f(x)=ax^2+bx+c](https://tex.z-dn.net/?f=f%28x%29%3Dax%5E2%2Bbx%2Bc)
is given by the equation
![x=h](https://tex.z-dn.net/?f=x%3Dh)
, where h is the x-coordinate of the vertex and is equal to
![\frac{-b}{2a}](https://tex.z-dn.net/?f=%5Cfrac%7B-b%7D%7B2a%7D)
.
1.
![f(x)=4x^2-1 \\ a=4 \\ b=0 \\ \Downarrow \\ h=\frac{-0}{2 \times 4}=0 \\ \\ \hbox{the axis of symmetry:} \\ x=0](https://tex.z-dn.net/?f=f%28x%29%3D4x%5E2-1%20%5C%5C%0Aa%3D4%20%5C%5C%20b%3D0%20%5C%5C%20%5CDownarrow%20%5C%5C%0Ah%3D%5Cfrac%7B-0%7D%7B2%20%5Ctimes%204%7D%3D0%20%5C%5C%20%5C%5C%0A%5Chbox%7Bthe%20axis%20of%20symmetry%3A%7D%20%5C%5C%0Ax%3D0)
2.
![g(x)=x^2-8x+5 \\ a=1 \\ b=-8 \\ \Downarrow \\ h=\frac{-(-8)}{2 \times 1}=\frac{8}{2}=4 \\ \\ \hbox{the axis of symmetry:} \\ x=4](https://tex.z-dn.net/?f=g%28x%29%3Dx%5E2-8x%2B5%20%5C%5C%0Aa%3D1%20%5C%5C%20b%3D-8%20%5C%5C%20%5CDownarrow%20%5C%5C%20h%3D%5Cfrac%7B-%28-8%29%7D%7B2%20%5Ctimes%201%7D%3D%5Cfrac%7B8%7D%7B2%7D%3D4%20%5C%5C%20%5C%5C%0A%5Chbox%7Bthe%20axis%20of%20symmetry%3A%7D%20%5C%5C%0Ax%3D4)
3.
![h(x)=-3x^2-12x+1 \\ a=-3 \\ b=-12 \\ \Downarrow \\ h=\frac{-(-12)}{2 \times (-3)}=\frac{12}{-6}=-2 \\ \\ \hbox{the axis of symmetry: \\ x=-2](https://tex.z-dn.net/?f=h%28x%29%3D-3x%5E2-12x%2B1%20%5C%5C%0Aa%3D-3%20%5C%5C%20b%3D-12%20%5C%5C%20%5CDownarrow%20%5C%5C%20h%3D%5Cfrac%7B-%28-12%29%7D%7B2%20%5Ctimes%20%28-3%29%7D%3D%5Cfrac%7B12%7D%7B-6%7D%3D-2%20%5C%5C%20%5C%5C%0A%5Chbox%7Bthe%20axis%20of%20symmetry%3A%20%5C%5C%0Ax%3D-2)
The functions ranked from least to greatest based on their axis of symmetry: h(x), f(x), g(x).
Answer:
40 in²
Step-by-step explanation:
Surface area = 4 triangles + square
= 4[½ × 4 × 3] + 4²
= 4(6) + 16
= 40 in²
Math Sucks hahahahahahahahahahahahaha