Answer:
Hyperbola
Step-by-step explanation:
The polar equation of a conic section with directrix ± d has the standard form:
r=ed/(1 ± ecosθ)
where e = the eccentricity.
The eccentricity determines the type of conic section:
e = 0 ⇒ circle
0 < e < 1 ⇒ ellipse
e = 1 ⇒ parabola
e > 1 ⇒ hyperbola
Step 1. <em>Convert the equation to standard form
</em>
r = 4/(2 – 4 cosθ)
Divide numerator and denominator by 2
r = 2/(1 - 2cosθ)
Step 2. <em>Identify the conic
</em>
e = 2, so the conic is a hyperbola.
The polar plot of the function (below) confirms that the conic is a hyperbola.
Answer:
In the same place, And 4.0
Step-by-step explanation:
To obtain the total surface we have to calculate the surface of the 4 triangles and add up the areas (remember that the area of a triangle is (b*h)/2 , b is the base, h is the height ).
We will caculate first the area of the base triangle for that we considerer the fact that it is an equilateral triangle with sides of lenght 6 cm, now we calculate the height, I am going to draw please wait a moment
using the pythagorean theorem we have that
![\begin{gathered} h^2=6^2cm^2-3^2\operatorname{cm}=27cm^2 \\ h=\text{ }\sqrt[]{27\text{ }}cm \end{gathered}](https://tex.z-dn.net/?f=%5Cbegin%7Bgathered%7D%20h%5E2%3D6%5E2cm%5E2-3%5E2%5Coperatorname%7Bcm%7D%3D27cm%5E2%20%5C%5C%20h%3D%5Ctext%7B%20%7D%5Csqrt%5B%5D%7B27%5Ctext%7B%20%7D%7Dcm%20%5Cend%7Bgathered%7D)
Then, the area of the triangle is 6*h/2 = 3h = 15.59 cm^2.
Now we calculate the area of the other 3 triangles, notice that those triangles have the same base and height so we will calculate for one of them and multiply by 3. From the image we know that the height is 15cm and the base is 6 cm so the area is 45cm^2, and 45*3 cm^2 = 135cm^2.
Finally we add up all the areas:
I believe the answer is A
