 |
|
|
|
|
|
|
|
|
The width of an arch |
2007-03-28 |
|
From Brad:
A parabolic arch satisfies the equation y= 16 - 0.25x^2 for y >= 0. Find the width w of the arch.
Answered by Penny Nom. |
|
|
|
|
|
|
The volume of a cylinder |
2007-03-28 |
|
From bob:
how do you find the volume of a cylinder that is 12 centimeters wide and 16 centimeters tall?
Answered by Penny Nom. |
|
|
|
|
|
|
Names of solid figures |
2007-03-28 |
|
From Debbie:
What is the name of the solid figure: 1) base with 5 equal sides and faces that are 5 triangles 2) all 6 faces are squares and 3) 2 congruent pentagons for bases and 5 rectangular faces. Please help! Thanks
Answered by Penny Nom. |
|
|
|
|
|
|
5 square metres |
2007-03-28 |
|
From Allan:
please confirm if an area of 5 square metres is different from 5m^2 (5metres squared)
Answered by Penny Nom. |
|
|
|
|
|
|
The angles in a right triangle |
2007-03-28 |
|
From Golaan:
I need the to understand the formula for finding either of the acute angles of a right triangle given it's hieght length and base length.
I want to find the degrees of either accute angle. So for this example I have a right triangle with a height of 410 meters and a base length of 1,700 meters.
I don't understand cosine, sine, and tangent or the other ones at all. So if the solution includes those (which I believe it does) could b very verbose yet in a very elementary way?
The purpose of ths is that I have to define the general incline angles (or grade) of various areas of terrain. I know the distance by map and also the the altitude at either endpoint.
Answered by Penny Nom. |
|
|
|
|
|
|
The foci of an ellipse |
2007-03-27 |
|
From Brad:
I am trying to figure out how to find the foci of an ellipse x^2/7 + y^2/16 = 1.
Since 16 is the largest denominator I know the major axis is going to be the y axis.
Do I now take 7-c^2=16. c^2=16-7, c^2=9, c=3. So is my foci (0,+-3).
Answered by Penny Nom. |
|
|
|
|
|
|
Slopes of perpendicular lines |
2007-03-27 |
|
From Mykolyn:
How do you find the slope of a line that is perpendicular to the graph of:
y= -1/2x+4?
Answered by Leeanne Boehm and Sara Ulmer. |
|
|
|
|
|
|
Solve for x and y |
2007-03-27 |
|
From anthony:
solve y=4x and x+y=5
Answered by Sara Ulmer. |
|
|
|
|
|
|
Cut a cake into four pieces |
2007-03-27 |
|
From haley:
A cake measures 10 inches x 10 inches. The cake was cut into 4 pieces that were the same size. What could the size be of each piece?
Answered by Penny Nom. |
|
|
|
|
|
|
Factoring a trinomial |
2007-03-27 |
|
From Kim:
Hi, could you please help me solve this.
3x(squared) +20x - 7
Answered by Leeanne Boehm. |
|
|
|
|
|
|
Nine character passwords |
2007-03-27 |
|
From oliver:
suppose a password consisted of a string of nine characters from the
english alphabet(26 characters). if each possible password could be tested
in a microsecond,how long would it take to test all possible passwords?
Answered by Penny Nom. |
|
|
|
|
|
|
The volume of a trough |
2007-03-27 |
|
From Tracy:
I need help trying to find the volume of a 9 ft long trough that has two
equilateral triangles on the end. When the water of the trough is 2 feet
deep and its depth keeps increasing by 1/2 ft/minute. I have to figure
out at what rate the water is flowing into the trough.
Can you point me in the right direction for finding the equation
for the volume of the trough?
Answered by Penny Nom. |
|
|
|
|
|
|
Which compounding period will make the interest rate be as low as possible? |
2007-03-27 |
|
From lilly:
if i decide to loan a friend 12000 and he said that he will pay it back in a single payment of 16000 after 5 years.
which compounding period will make the interest rate be as low as possible? daily or yearly?
how can i calculate each (yearly compound and daily compound)?
Answered by Penny Nom. |
|
|
|
|
|
|
Schedule for a 10 team league |
2007-03-27 |
|
From Pete:
I don't know if this question involves a math solution, but I am running out of ideas.
I have a 10 team league. Each team must play each other once only. I can't seem
to match this up and get stuck at the end. Please help. Thanks, Pete
Answered by Penny Nom. |
|
|
|
|
|
|
A triangular prism |
2007-03-26 |
|
From Tom:
Hi, I need to find a container in the shape of a triangular prism that will fit
four table tennis balls (this is for a math project!). These balls have a
diameter of 4cm, so a radius of 2. I know that the formula for finding
an incircle from a triangle is:
radius of incircle =
2area of triangle / perimeter of triangle
But I need to know the length of one side of the triangle from the incircle
(the triangle needs to be equalateral).
Can you help me find a formula for this?
Thanks so much!
Tom
Answered by Penny Nom. |
|
|
