Find the surface area of this rectangular solid.
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Answer:
(x + 7)^2 + (y + 1)^2 = 25.
Step-by-step explanation:
The center of a circle is easy to set up. According to the formula below, the formula for the circle will be (x - a)^2 + (y - b)^2 = r^2.
In this case, a = -7 and b = -1, so we have...
(x - (-7))^2 + (y - (-1))^2 = r^2
(x + 7)^2 + (y + 1)^2 = r^2
To get the radius, we need to find the distance between the center and the point on the circle. The distance formula is d = sqrt((x2 - x1)^2 + (y2 - y1)^2).
In this case, x2 = -4, x1 = -7, y2 = 3, and y1 = -1.
sqrt((-4 - -7)^2 + (3 - -1)^2) = sqrt((-4 + 7)^2 + (3 + 1)^2) = sqrt((3)^2 + (4)^2) = sqrt(9 + 16) = sqrt(25) = plus or minus 5.
Since distance can only be positive, the distance is 5 units, meaning that the radius is 5 units.
5^2 = 25
So, your equation should be (x + 7)^2 + (y + 1)^2 = 25.
Hope this helps!
So hmmm check the picture below
so... the vertex is "p" distance from the focus and the directrix, thus, the vertex is really half-way between both
in this case, 2 units up from the focus or 2 units down from the directrix, and thus it lands at 3,3
now, the "p" distance is 2, however, the directrix is up, the focus point is below it, the parabola opens towards the focus point, thus, the parabola is opening downwards, and the squared variable is the "x"
because the parabola opens downwards, "p" is negative, and thus, -2
now, let's plug all those fellows in then
so... the vertex is "p" distance from the focus and the directrix, thus, the vertex is really half-way between both
in this case, 2 units up from the focus or 2 units down from the directrix, and thus it lands at 3,3
now, the "p" distance is 2, however, the directrix is up, the focus point is below it, the parabola opens towards the focus point, thus, the parabola is opening downwards, and the squared variable is the "x"
because the parabola opens downwards, "p" is negative, and thus, -2
now, let's plug all those fellows in then