Answer:

Step-by-step explanation:
A sequence is defined by the recursive formula
If
then
for 
for 
for 
for 
Answer:
√7 ≈ 2.646
Step-by-step explanation:
The law of cosines is applicable. It tells you ...
c² = a² + b² - 2ab·cos(C) . . . . . where a, b, c are triangle side lengths, and angle C is opposite side c.
Filling in the given information, you have ...
c² = 2² + 3² - 2·2·3·cos(60°) = 4 + 9 - 12·(1/2) = 7
c = √7 ≈ 2.646
The length of the third side is √7, about 2.646 units.
<h3>
Answer: 1 hour</h3>
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Explanation:
In the method I show below, the value 600,000 liters is never used. All that matters are the two values of 100 minutes and 150 minutes.
Pipe A drains the pool in 100 minutes. The rate it drains the pool is 1/100 of a pool per minute. If you multiply 1/100 by 100, then you'll represent 1 full job being done (that job being draining the pool).
Pipe B drains the pool in 150 minutes. Pipe B's rate is 1/150 of a job per minute.
In total, the combined rate is
1/100 + 1/150 = 3/300 + 2/300 = 5/300 = 1/60 of a pool per minute
This means it takes them 60 minutes to drain the pool assuming the two pipes work the most efficiently together (ie one pipe doesn't hinder the other). Since 60 minutes = 1 hour, it's much easier to say it takes 1 hour to drain the pool with both pipes working together.
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We can get this same answer through solving the equation
1/x + 1/y = 1/z
for z. Use x = 100 and y = 150.