For this case we have the following equation:
r = 9 sin (θ)
In addition, we have the following change of variables:
y = r * sine (θ)
Rewriting the equation we have:
r = 9 sin (θ)
r = 9 (y / r)
r ^ 2 = 9y
On the other hand:
r ^ 2 = x ^ 2 + y ^ 2
Substituting values:
x ^ 2 + y ^ 2 = 9y
Rewriting:
x ^ 2 + y ^ 2 - 9y = 0
Completing squares:
x ^ 2 + y ^ 2 - 9y + (-9/2) ^ 2 = (-9/2) ^ 2
Rewriting:
x ^ 2 + 1/4 (2y-9) ^ 2 = 81/4
4x ^ 2 + (2y-9) ^ 2 = 81
Answer:
The Cartesian equation is:
4x ^ 2 + (2y-9) ^ 2 = 81
we have point (-6, - 1)
Now we will put these points in each equation,
y = 4x +23
put x = -6 and y = -1
-1 = 4 (-6) +23
-1 = -24 + 23
-1 = -1
LHS = RHS, so this equation has (-6 , -1) as solution.
y = 6x
put x = -6 and y = -1
-1 = 6 (-6)
-1 not= -36
LHS is not equal RHS, so (-6 , -1) is not a solution for that equation,
y = 3x - 5
put x = -6 and y = -1
-1 = 3 (-6) - 5
-1 = -18 - 5
-1 not= -23
LHS is not equal RHS, so (-6 , -1) is not a solution for that equation,
y= 1/6 x
put x = -6 and y = -1
-1 = -6/6
-1 = -1
LHS = RHS, so (-6 , -1) is a solution for that equation,
Answer:
y = - 8
Step-by-step explanation:
y - 16 - 3y = 0
Group like terms
y - 3y - 16 = 0
Add similar elements: y - 3y = - 2y
- 2y - 16 = 0
Add 16 to both sides
- 2y - 16 + 16 = 0 + 16
Simplify
- 2y = 16
Divide both sides by - 2
= 
Simplify
: y

Apply the fraction rule: 
= 
Divide the numbers: 
= y
Simplify
: - 8

Apply the fraction rule: 

Divide the numbers:
= 8
= - 8
y = - 8
Observe attached picture.
On picture we have:
A = height of flagpole = x ft
B = length of flagpole's shadow = 24 ft
C = height of sign = 6 ft
D = length of sign's shadow = 3 ft
When we draw a picture representing this problem we can also add another line marked in red. This way we can see that we have two right-angle triangles. We can see that both have same angle marked with α.
We can apply trigonometry rules to find height of flagpole.
From small triangle containing sign we can find tangens function:

Similarly we can do for large triangle containing flagpole:

We see that these two equations have same left sides. This means that their right sides must also be same:

We can solve for A:

Height of flagpole is 48 feet.