Answer:
The area of the rectangle is increasing at a rate of 84 square centimeters per second.
Step-by-step explanation:
The area for a rectangle is given by the formula:

Where <em>w</em> is the width and <em>l</em> is the length.
We are given that the length of the rectangle is increasing at a rate of 6 cm/s and that the width is increasing at a rate of 5 cm/s. In other words, dl/dt = 6 and dw/dt = 5.
First, differentiate the equation with respect to <em>t</em>, where <em>w</em> and <em>l</em> are both functions of <em>t: </em>
![\displaystyle \frac{dA}{dt}=\frac{d}{dt}\left[w\ell]](https://tex.z-dn.net/?f=%5Cdisplaystyle%20%5Cfrac%7BdA%7D%7Bdt%7D%3D%5Cfrac%7Bd%7D%7Bdt%7D%5Cleft%5Bw%5Cell%5D)
By the Product Rule:

Since we know that dl/dt = 6 and that dw/dt = 5:

We want to find the rate at which the area is increasing when the length is 12 cm and the width is 4 cm. Substitute:

The area of the rectangle is increasing at a rate of 84 square centimeters per second.
Answer:
C. 75°
Step-by-step explanation:
We have been given a circle and we are asked to find the measure of angle AEC.
We will use Intersecting chords theorem to find the measure of angle AEC, which states that measure of angle formed inside a circle by two intersecting chords is one half the sum of the measure of the arcs intercepted by the angle and its vertical angle.
We can see that measure of arc AC is 110 degrees and measure of its vertical arc BD is 40 degrees.



Therefore, measure of angle AEC is 75 degrees and option C is the correct choice.
Answer:
"
is irrational for every nonzero integer x"
Step-by-step explanation:
The original statement is
"
is rational for some nonzero integer x."
The negation is technically:
"It is NOT true that
is rational for some nonzero integer x."
So it's expressing that it's false that
can be rational for some nonzero integer x.
This just means that
is always irrational when x is a nonzero integer.
Which can be worded as
"
is irrational for every nonzero integer x"
I believe the answer is 11/15 .