Step-by-step explanation:

The rate of change of the size of the diagonal is; 25.2 ft/s
By Pythagoras theorem;
The length, l of a diagonal of a rectangle whose sides have lengths x and y is;
In essence; the length of the diagonal is dependent on the length, x and y of the sides.
Therefore;
(dl/dt)² = (dx/dt)² + (dy/dt)²
where;
- (dx/dt) = 19 ft/s
- (dy/dt) = -15 ft/s
Therefore,
(dl/dt)² = 19² + (-15)²
(dl/dt)² = 361 + 225
dl/dt = √586
dl/dt = 25.2
Therefore, the size of the diagonal is changing at a rate of; 25.2 ft/s.
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brainly.com/question/12559989
Answer:
8
Step-by-step explanation:
a*b=72
a=9
9*b=72
b=72/9
b=8
Answer: (3, 18)
Step-by-step explanation: Where the lines corss the x does not go over 10 so the only other option is a 3. If you cut the box hori in half in you mind, the top half being 15-20 and the bottom half bring 10-14, then you can see the lines cross on the top half. Meaning it’s at 18 not 12.