Answer:
it would be answer a
Step-by-step explanation:
that's all i have
Answer:
x₁ = -4
x₂ = 3
Step-by-step explanation:
x²+ x + 12 = 0
x = {-1±√((1²)-(4*1*-12))} / (2*1)
x = {-1±√(1+48)} / 2
x = {-1±√49} / 2
x = {-1±7} / 2
x₁ = {-1-7} / 2 = -8/2 = -4
x₂ = {-1+7} / 2 = 6/2 = 3
Check:
x₁
-4² + (-4) - 12 = 0
16 - 4 - 12 = 0
x₂
3² + 3 - 12 = 0
9 + 3 - 12 = 0
Step-by-step explanation:
There are no choices available, so here is a graph of that equation. Simply compare it to the answer.
Yay, derivitives
I'mma ignore that x is the shorter side because I don't know which one has to be shorter yet
we need to find the max area
but with 3 sides
area=LW
let's say the sides are z and y
zy=area
and the relatiionship between them is
hmm,
z+2y=1200
because one side has no fencing
so
z+2y=1200
solve for z
z=1200-2y
sub for z in other
(1200-2y)(y)=area
expand
1200y-2y²=area
take derivitive
1200-4y=dy/dx area
max is where dy/dx goes from positive to negative
solve for where dy/dx=0
1200-4y=0
1200=4y
300=y
at y<300, dy/dx<0
at y>300, dy/dx>0
so at y=300, that is the max
then
z=1200-2y
z=1200-2(300)
z=1200-600
z=600
so then
z=600
y=300
300<600
so the shorter side would be y
so then we see our choices and noticed that
erm
I think it is f(x)=1200x-2x²
takind the derivitive yeilds none of the others
so ya, you are right