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Lera25 [3.4K]
3 years ago
8

If P=(-2,5) and (x,-27), find all numbers x such that the vector represented by PQ has length -40

Mathematics
1 answer:
Akimi4 [234]3 years ago
8 0

Answer:

  x ∈ {-26, 22}

Step-by-step explanation:

A graph shows that the points (-26, -27) and (22, -27) lie on a circle of radius 40 centered at (-2, 5). That is, if Q is either one of these points, the vector PQ will have a length of 40:

  • √((-26-(-2))^2 +(-27-5)^2) = √((-24)^2 +(-32)^2) = √1600 = 40
  • √((22 -(-2))^2 +(-27 -5)^2) = √(24^2 +(-32)^2) = √1600 = 40

You can call it -40 if you like, but you have to define what negative length means when you do that.

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Given as :

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The amount of liquid in the tank at the start is 1000 L. If water is pumped in at a rate of 10 L/s, then after <em>t</em> s there will be (1000 + 10<em>t</em> ) L of liquid in the tank. But we're also removing 25 L from the tank per second, so there is a net "gain" of 10 - 25 = -15 L of liquid each second. So the volume of liquid in the tank at time <em>t</em> is (1000 - 15<em>t </em>) L. Then the concentration of chlorine per unit volume is <em>c</em> (<em>t</em> ) divided by this volume.

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