Please help please , thanks

Area 9 perimeter 20 what is the length and width

oksano4ka [1.4K]

Answer:4.5 x 2

Step-by-step explanation:

4.5 x 2 = 9

Hope it helps

8 0

3 years ago

What are the coordinates of the focus of the parabola?

Dima020 [189]

This is a tough one. the general form of a parabola is $(x-h) ^{2} =4p(y-k)$ , where h and k are the coordinates of the vertex and p is the distance from the vertex to the focus. In order to get our parabola into this form and solve for p (which will give us our focal point), we have to complete the square. Set the parabola equal to 0, then move over the constant to get this equation: $- \frac{1}{16} x^{2} -x=-2$ . In order to complete the square, the leading coefficient on the squared term has to be a +1. Ours is a $- \frac{1}{16}$ , so we have to factor that out of the x terms. When you do that you end up with $- \frac{1}{16} ( x^{2} +16x)=-2$ . Now we can complete the square by taking half the linear term, squaring it, and adding it to both sides. Our linear term is 16, so half of 16 is 8 annd 8 squared is 64. HOWEVER, on the left side, that $- \frac{1}{16}$ is still hanging out in front, which means that when we add in 64, we are actually adding in $- \frac{1}{16} *64$ which is -4. Now here's what we have: $- \frac{1}{16} ( x^{2} +16x+64)=-2-4$ which simplifies to $- \frac{1}{16}( x^{2} +16x+64)=-6$ . Creating the perfect square binomial on the left was the point of this (to give us our vertex), so when we do that we have $- \frac{1}{16} (x+8) ^{2} =-6$ . Now just for simplicity, we will take baby steps. Move the -6 back over by addition and set it back equal to y: $- \frac{1}{16}(x+8) ^{2}+6=y$ . Now we will work on getting into standard form. Move the 6 back over by the y (baby steps, remember) to get $- \frac{1}{16} (x+8) ^{2} =y-6$ . Multiply both sides by -16 to get our "p" on the right: $(x+8) ^{2} =-16(y-6)$ . We need to use our "4p" part of the standard form to find the p, which is the distance from the vertex to the focus. 4p=-16, and p = -4. That means that the focus is 4 units below the vertex. Let's figure out what the vertex is. From our equation, the vertex is ( -8, 6), and since this is an upside-down opening parabola, the focus will be aligned with the x-coordinate of the vertex. So our focus lies 4 units below 6 (6 is the y coordinate of the vertex which indicates up and down movement), so our focus has coordinates of (-8, 2), the first choice above. Told you it was a tough one! These conics are quite challenging!

7 0

3 years ago

Solve 2x2 − 12x + 20 = 0. 3 ± i 3 ± 2i 1 ± 2i 2 ± 3i

makkiz [27]

This is the concept of quadratic equations, solving the equation 2x^2-12x+20=0 using the formula we get:
x=[-b+/-sqrt(b^2-4ac)]/(2a)
from our equation, a=2,b=-12 and c=20
x=[-(-12+/-sqrt((-12)^2-4*2*20)]/(2*2)
x=[12+/-sqrt(144-160]/4
x=[12+/-sqrt(-16)]/4
x=[12+/-4i]/4
x=[3+\-i]
the answer is A] 3+/-i

7 0

3 years ago

What is the volume of a sphere that has a diameter of 36 yd?

Katen [24]

Volume=(4/3)pi(r^3)

radius=1/2diameter
d=36
radius=1/2 36
radius=18

subsitute
volume=4/3 pi 18^3
volume=4/3 pi 5832
volume=23328/3 pi
volume=7776pi

aprox pi to 3.14
volume=7776 times 3.14
volume=24416.64

answer is 24416.64 yd^3

8 0

4 years ago

Solve for x in the equation ]x^{2} - 12x + 59 = 0

Vedmedyk [2.9K]

Step-by-step explanation:

$x^{2} - 12x + 59 = 0$