Assignment 3

course Mth 158

|????U??????assignment #003003. `query 3

College Algebra

05-31-2009

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11:04:42

query R.3.16 \ 12 (was R.3.6) What is the hypotenuse of a right triangle with legs 14 and 48 and how did you get your result?

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RESPONSE -->

14^2 + 48^2 = 196 + 2304 then sqaure this number giving

48

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11:05:44

** The Pythagorean Theorem tells us that

c^2 = a^2 + b^2, where a and b are the legs and c the hypotenuse. Substituting 14 and 48 for a and b we get

c^2 = 14^2 + 48^2, so that

c^2 = 196 + 2304 or

c^2 = 2500.

This tells us that c = + sqrt(2500) or -sqrt(2500). Since the length of a side can't be negative we conclude that c = +sqrt(2500) = 50. **

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RESPONSE -->

Made a careless mistake: add 196+2304 = 2500 and square root 2500 hence 50

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11:07:04

query R.3.22 \ 18 (was R.3.12). Is a triangle with legs of 10, 24 and 26 a right triangle, and how did you arrive at your answer?

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RESPONSE -->

10*10 = 100

24*24 = 576

and square root of 676 is 26 so this is a right triangle

I used the pythagorean theorem

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11:07:36

** To find the volume and surface are a sphere we use the given formulas:

Volume = 4/3 * pi * r^3

V = 4/3 * pi * 3^3

V = 4/3 * pi * 27

V = 36pi m^3

Surface Area = 4 * pi * r^2

S = 4 * pi * 3^2

S = 4 * pi * 9

S = 36pi m^2. **

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RESPONSE -->

manipulating the Pythagoren Theorem

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11:15:18

query R.3.50 \ 42 (was R.3.36). A pool of diameter 20 ft is enclosed by a deck of width 3 feet. What is the area of the deck and how did you obtain this result?

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RESPONSE -->

base x height so 20*3 = 60 feet

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11:20:37

** The deck plus the pool gives you a circle of radius 10 ft + 3 ft = 13 ft.

The area of the deck plus the pool is therefore pi * (13 ft)^2 = 169 pi ft^2.

So the area of the deck must be

deck area = area of deck and pool - area of pool = 169 pi ft^2 - 100 pi ft^2 = 69 pi ft^2. **

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RESPONSE -->

right. because the diamter is given we can assume the pool is a circle.

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11:21:13

Query Add comments on any surprises or insights you experienced as a result of this assignment.

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RESPONSE -->

with geometry type questions you have to think beyond the box sometimes and imagine the shapes

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???F????????????assignment #003

003. `query 3

College Algebra

05-31-2009

Let me know if you have questions on any of these problems or the given solutions.

Do begin using the 'open' query documents.