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
Method 1:
Convert the mixed number to the improper fraction:
Make the product:
<em>canceled 2</em>
Method 2:
<em>use the distributive property a(b + c) = ab + ac</em>
Answer:
13 pieces
Step-by-step explanation:
First we convert 4m into cm :
1m = 100cm
4m = 400cm
Now we need to figure out how many 30s go into 400 :
400 ÷ 30 = 13 remainder 10
So 13 pieces can be cut from the ribbon
Hope this helped and have a good day
Answer:
20 meters
Step-by-step explanation:
Firstly we need to know that distance = speed * time
In this particular question, we have the time and the speed, we are only told to find the distance.
Now as we can see, the units are not consistent. While the average speed is 30mph, the time is not in hours but minutes. So practically, we have to convert the time to hours.
Since there are 60 minutes in an hour, the number of hours in 40 minutes would be 40/60 = 2/3 hours.
Now we can proceed to find the distance. We simply multiply the average speed with the time.
Hence, that is 30 * 2/3 = 20 meters
