 |
|
|
|
|
|
|
|
|
The path of a small sailboat |
2008-11-19 |
|
From jane:
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.
Answered by Harley Weston. |
|
|
|
|
|
|
Jogging around a circular track |
2008-11-19 |
|
From kim:
Joan wants to jog 10 miles on a circular track 1/4 miles in diameter. How many times must she circle the track?
Answered by Penny Nom. |
|
|
|
|
|
|
evaluate (24 + n) - 6 if n = 4 |
2008-11-19 |
|
From A student:
evaluate (24=n)-6 if n=4
Answered by Penny Nom. |
|
|
|
|
|
|
Factoring |
2008-11-19 |
|
From Neji:
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?
Answered by Harley Weston. |
|
|
|
|
|
|
Sigma in a normal distribution |
2008-11-18 |
|
From Justin:
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
Answered by Harley Weston. |
|
|
|
|
|
|
A normal distribution problem |
2008-11-18 |
|
From Mark:
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)
Answered by Harley Weston. |
|
|
|
|
|
|
An algebraic exercise with fractions and radicals |
2008-11-18 |
|
From Rubén:
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
Answered by Rubén Osuna. |
|
|
|
|
|
|
Juanita and Jim each think of a number. |
2008-11-18 |
|
From Maria:
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?
Answered by Penny Nom. |
|
|
|
|
|
|
Insulation in an attic |
2008-11-18 |
|
From Scott:
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.
Answered by Harley Weston. |
|
|
|
|
|
|
How do I compare fractions and decimals? |
2008-11-18 |
|
From Alexis:
How do I compare fractions and decimals ?
Answered by Penny Nom. |
|
|
|
|
|
|
A circle and a chord |
2008-11-17 |
|
From Lydz:
The circle has a radius of 8cm
The chord is 13cm long.
Find the distance from the centre of the circle, to the chord.
Answered by Penny Nom. |
|
|
|
|
|
|
How do you solve " (x-4)^3/2 = -6 "? |
2008-11-17 |
|
From Jim:
How do you solve " (x-4)^3/2 = -6 " ?
Answered by Penny Nom. |
|
|
|
|
|
|
The volume is decreased by 25% |
2008-11-17 |
|
From Wanda:
If the volume of a sphere is decreased by 25%, what is the new equation?
Answered by Penny Nom. |
|
|
|
|
|
|
The height, base and perimeter of a triangle |
2008-11-17 |
|
From Zack:
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.
Answered by Penny Nom. |
|
|
|
|
|
|
How do you solve "logx^4=4? |
2008-11-17 |
|
From Scott:
How do you solve "logx^4=4"?
Answered by Penny Nom. |
|
|
