Ok so we have the parabola at origin of y=-12 and crosses x-axis at points x=1,8 so, we could just look at where it crosses the x-axis and find it directly from there. it crosses x-axis at 1 and 8 so the answer can only be A to fit this criteria
Alright,
directix is y=something so it opens down or up
we use
(x-h)²=4p(y-k)
the vertex is (h,k)
and p is distance from focus to vertex
if focus is above directix, p is positive
if focus is below directix, p is negative
so we gts
focus=(1,1)
directix is y=-1
1>-1
focus is above
oh, vertex is in middle of focus and directix
so
beteeen (1,1) and y=-1 is, hmm
that is a distance of 2 vertically
2/2=1
1 down from (1,1) is (1,0)
vertex is (1,0)
p=1
so
(x-1)²=4(1)(y-0)
solving for y to get into f(x)=something form
(x-1)²=4y
y=1/4(x-1)²
f(x)=1/4(x-1)²
4th option
X=width of the lake
y=length of the lake.
we set out this system of equiations
x*y=9/20
x=y/5
we solve by sustitution method
(y/5)*y=9/20
y²/5=9/20
y²=(5*9)/ 20
y²=2.25
y=√2.25=1.5
x=y/5
x=1.5/5=0.3
Solution:
width of the lake=0.3 miles
lenght of the lake=1.5 miles
Answer:
The surface = pi*10cm2
Step-by-step explanation:
The area of any rectangle is Base * Height,
We know that the square originally has 10cm High, when is rolled to form a cylinder, it's new shape has a bottom side that is equals to a circle.
The length of a circle is 2*pi*Radio= pi*Diameter.
Since the square has the same length in each side, we know that pi*Diameter= 10cm*pi
The surface (area) of the cylinder is= Base * Height= 10cm*10cm*pi
