Answer:
r = 144 units
Step-by-step explanation:
The given curve corresponds to a parametric function in which the Cartesian coordinates are written in terms of a parameter "t". In that sense, any change in x can also change in y owing to this direct relationship with "t". To find the length of the curve is useful the following expression;

In agreement with the given data from the exercise, the length of the curve is found in between two points, namely 0 < t < 16. In that case a=0 and b=16. The concept of the integral involves the sum of different areas at between the interval points, although this technique is powerful, it would be more convenient to use the integral notation written above.
Substituting the terms of the equation and the derivative of r´, as follows,

Doing the operations inside of the brackets the derivatives are:
1 ) 
2) 
Entering these values of the integral is

It is possible to factorize the quadratic function and the integral can reduced as,

Thus, evaluate from 0 to 16
The value is 
Answer:
In this equation, we can start by understanding that "x" has a value of 8, as given in the ordered pair. When multiplied by 5, this leads to "40 - 2y = 30". Next, we can subtract 40 from both sides of the equation. This leads us to a value of "-2y = -10". The next step would be to divide both sides by -2 as a way of isolating "y", which leads us to a final value of "y = 5". The final ordered pair would be (8,5).
You would find this by doing 250 times 20% which is .2 and you would get 50 so you would add 250 plus 50 and get 300.
The answer is $300
Dr /dt = 7
A = pi r^2
dA / dr = 2pir
dA/dt = dA/dr * dr/dt = 2pir * 7 = 14pir
when r = 12 rate of change of the area = 14*pi*12 = 168pi
= 527.79 cm^2 / minute to nearest hundredth
The first on is the tenth place
the second one is the tenth place
the third one is the tenth place
the last one is the millionth place
hope i helped :) i might be wrong though