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The path of a small sailboat |
2008-11-19 |
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jane pose la question :
a sailor in a small sailboat encounters shifting winds. she sails 2.00 km East
then 3.40 km North East, then an additional distance in an unknown direction. Her final position
is 6.68 km directly east of the starting point. find the magnitude & direction
of the third leg of the voyage.
Harley Weston lui répond. |
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Jogging around a circular track |
2008-11-19 |
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kim pose la question :
Joan wants to jog 10 miles on a circular track 1/4 miles in diameter. How many times must she circle the track?
Penny Nom lui répond. |
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evaluate (24 + n) - 6 if n = 4 |
2008-11-19 |
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A student pose la question :
evaluate (24=n)-6 if n=4
Penny Nom lui répond. |
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Factoring |
2008-11-19 |
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Neji pose la question :
How do you factor (y-z) (y+z) (y^4+y^2z^2+z^4) and get (y+z)(y^2-yz+z^2) (y-z) (y^2+yz+z^2) as the answer?
Harley Weston lui répond. |
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Sigma in a normal distribution |
2008-11-18 |
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Justin pose la question :
Suppose the random variable Y can be described by a normal curve with
Mu=40. For what value of the standard deviation is
P(20 less than or equal to Y less than or equal to 60) = 0.50
-Justin
Harley Weston lui répond. |
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A normal distribution problem |
2008-11-18 |
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Mark pose la question :
Final Averages are typically approximately normally distributed with a mean of 72 and a standard deviation of 12.5.
your professor says that the top 8% of the class will receieve an A, the next 20%, a B, the next 42%, a C and the bottom 12%, an F.
a. What average must you exceed to obtain an A?
b. What Average must you exceed to receieve a grade better than a C?
c. What average must you obtain to pass the course? (you'll need a D or better)
Harley Weston lui répond. |
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An algebraic exercise with fractions and radicals |
2008-11-18 |
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Rubén pose la question :
Question from Rubén, a teacher:
I have the ecuation:
U = [yb / (ab+a^2)]^1/2 + [ya / (ab+b^2)]^1/2
I know for sure this reduces to
U = [y (1/a + 1/b)]^1/2
but I cannot find a way to get into that result!
Thanks
Rubén Osuna lui répond. |
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Juanita and Jim each think of a number. |
2008-11-18 |
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Maria pose la question :
Juanita and Jim each think of a number. Juanita's number is 8 more than Jim's number. The product of the two numbers is 65. What is Jim's number?
Penny Nom lui répond. |
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Insulation in an attic |
2008-11-18 |
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Scott pose la question :
A homeowner wishes to insulate her attic with fiberglass insulation to
conserve energy. The insulation comes in 40-cm-wide rolls that are cut
to fit between the rafters in the attic. If the roof is 6 m from peak to eave
and the attic space is 2 m high at the peak, how long does each of the
pieces of insulation need to be? Round to the nearest tenth.
Harley Weston lui répond. |
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How do I compare fractions and decimals? |
2008-11-18 |
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Alexis pose la question :
How do I compare fractions and decimals ?
Penny Nom lui répond. |
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A circle and a chord |
2008-11-17 |
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Lydz pose la question :
The circle has a radius of 8cm
The chord is 13cm long.
Find the distance from the centre of the circle, to the chord.
Penny Nom lui répond. |
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How do you solve " (x-4)^3/2 = -6 "? |
2008-11-17 |
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Jim pose la question :
How do you solve " (x-4)^3/2 = -6 " ?
Penny Nom lui répond. |
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The volume is decreased by 25% |
2008-11-17 |
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Wanda pose la question :
If the volume of a sphere is decreased by 25%, what is the new equation?
Penny Nom lui répond. |
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The height, base and perimeter of a triangle |
2008-11-17 |
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Zack pose la question :
How would i calculate the height of a triangle if the base is 10cm and the area is 50cm²?
If possible how would i calculate the length around the the triangle.
Penny Nom lui répond. |
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How do you solve "logx^4=4? |
2008-11-17 |
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Scott pose la question :
How do you solve "logx^4=4"?
Penny Nom lui répond. |
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