Answer:
none of these
Step-by-step explanation:
Answer:
K(A+B)/A
Step-by-step explanation:
K = (AB)/(A+B)
K(A+B)=AB
K(A+B)/A=B
(x-h)^2=4P(y-k), vertex is (h,k)
P is distance from vertex to directix
remember to subtract P from the y value of the vertex (p-k) and that y value is the directix, y=p-k
nut
ok so one way is to just graph them on a graphing utility
remember if the graph opens up, then the directix is below that
or we can convert to 4P(y-k)=(x-h)^2 form where P is distance from directix
I will only convert the 1st one fully, you should be able to do the rest
1. y=-x^2+3x+8
multiply both sides by -1 since we don't like the x^2 term negative
-y=x^2-3x-8
add8 to both sides
-y+8=x^2-3x
take 1/2 of linear coeficient and square it and add to both sides
-3/2=-1.5
(-1.5)^2=2.25
-y+10.25=x^2-3x+2.25
factor perfect square
-y+10.25=(x-1.5)^2
force undistribute -1 in left side
(-1)(y-10.25)=something, we don't care anymore for now
factor out a 4 in -1
4(-1/4)(y-10.25)
k=10.25
p=-1/4=-0.25
directix=k-p=10.25-(-0.25)=10.5
directix is y=10.5
basically completee the square with x and find P by force factoring a 4 out
2. directix: y=-1.75
3. directix: y=1.5
4. directix: y=17.25
5. d: -37.5
6. d: 9.25
7. d=2.625
order them yourself
Answer:
slope is -2 and the y-intercept is 12
Step-by-step explanation:
a key thing to remember: x is always equal to 0 when finding the y-intercept.
so if you look at the table for where 0 is, you get the point (0,12) meaning the y-intercept is 12.
to find the slope use the equation: slope= change in y/change in x
you can use any two points to find this.
lets take the points of the x-intercept (6,0) and the y-intercept (0,12)
12-0/0-6
12/-6
-2 = slope
P = L + L + w + w
72 = 2(L) + 2(L-4)
Distribute
72 = 2(L) + 2(L) - 8
Add like terms
72 = 4(L) - 8
Subtract 8 from both sides
64 = 4(L)
Divide both sides by 4
16 = L
The length is 16. Now substitute that in the equation for finding w.
w = L - 4
w =