.
.
Math Central - mathcentral.uregina.ca
Quandaries & Queries
Q & Q
. .
Fresh off the press   Here are the newest items
added to Quandaries & Queries:
. .
start over

 
Page
37/774
Solve 2sin(2(theta))+sqrt(3)=0 2013-01-19
From Kaitlyn:
how do you solve 2sin(2(theta))+sqrt(3)=0 with the interval [0,2pi)
Answered by Penny Nom.
Maximize profit 2013-01-19
From Chris:
A firm has the following total revenue and total cost function.
TR=100x-2x^2
TC=1/3x^3-5x^2+30x
Where x=output
Find the output level to minimize profit and the level of profit achieved at this output.

Answered by Penny Nom.
5 1/2 cubic feet of sawdust 2013-01-19
From Vina:
I have a bale of sawdust that containes 5 1/2 cubic feet. How many will I need to make a cubic yard?
Answered by Penny Nom.
An equilateral triangle inscribed in a circle 2013-01-17
From Nicole:
How do you find the shaded region of a circle if an unshaded equilateral triangle in inscribed in it. The only other things I know about the problem are that the side lengths of the equilateral triangle are 14 inches.
Answered by Penny Nom.
The weight of a pipe full of water 2013-01-16
From joe:
how do you figure out the weight of a pipe full of water
Answered by Harley Weston.
A balance puzzle 2013-01-14
From Emily:
I'm stuck on this problem and feel that it can't work! The problem is: there is a door with a balance scale on it. In order to open the door, you have to use the 5 weights to balance the scale. On the left side you have 2 boxes to place the weights and on the right side you have 3. You're 5 weights are as follows: 1lbs, 2lbs, 3lbs, 4lbs, 5lbs. How do you place the weights so that the scale is balanced?
Answered by Penny Nom.
Percent as a fractional relationship 2013-01-14
From Kenneth:
What does the following indicate?

"A percent is another way of expressing the ratio or fractional relationship of two numbers."

I know what a ratio is, but the term "fractional relationship" confuses me.

I thank you for your reply.

Answered by Penny Nom.
A shed roof 2013-01-12
From christine:
A roof on a shed is 7.3 ft wide has an incline of 20 degrees what is the height?
Answered by Penny Nom.
A large ditch 2013-01-11
From steve:
hi
i have a large ditch to make a road entrance accross, the ditch is a green field on one side and a highway on the other side the ditch depth is 1.8m on the field side and 3.2 on the highway side the culvert pipe is 1,2m in diameter are you with me so far? the entrance from the highway will be 26m wide tapering in to 6m - ,20 m in from the highway there will be a concrete slab of 150mm over the top

the fall from highway to field must not exceed 1/8

any ideas how much stone it will need

Answered by Harley Weston.
How fast are we approaching each other? 2013-01-11
From Heather:
If I am skating at 7 mph, and a car drives towards me at 15 mph, how fast are we approaching each other?
Answered by Penny Nom.
The side lengths of a triangle 2013-01-07
From Katie:
How do I find the side lengths of a triangle knowing the base and its height?

Thank you,

Answered by Penny Nom.
A trig identity 2013-01-04
From Tehmas:
Prove sinC+sinD=2sin(C+D/2)cos(C-D/2)
Answered by Harley Weston.
The quadratic formula 2013-01-03
From itsel:
Find the discriminant ans use it to determine the use the quadratic formula to solve the equasion -2x^2+3x+2=0
Answered by Penny Nom.
Mod versus Rem in Turing 2013-01-01
From Eric:
I am a teacher teaching computer science using Turing. I am having difficulty understanding why one would use the mod operator versus the rem remainder operator.

Mod seems to make the resulting sign depend on the sign of the divisor, whereas rem makes the resulting sign depend on the dividend.

Examples:

11 mod 5 = 1 and 11 rem 5 =1
-11 mod 5 = 4 and -11 rem 5 = -1
11 mod -5 = -4 and 11 rem -5 =1
-11 mod -5 = -1 and -11 rem -5 = -1

What I can't understand is why this would matter. For example, -11 / 5 = -2.2 and 11 / -5 = -2.2 get the same result.
So how is a remainder dependent on the sign of one of the parts? What benefit would using one over the other have?

Any insight would be most helpful!

Eric

Answered by Harley Weston.
A triangular island 2012-12-29
From Udit:
A long time ago Mr Gibson found an island shaped as a triangle with three straight shores of length 3 km,4 km and 5 km. He declared an 'exclusion zone' around his island and forbade anyone to come within 1 km of his shore. What was the area of his exclusion zone?
Answered by Penny Nom.
 
Page
37/774

 

 


Math Central is supported by the University of Regina and The Pacific Institute for the Mathematical Sciences.

CMS
.

 

Home Resource Room Home Resource Room Quandaries and Queries Mathematics with a Human Face About Math Central Problem of the Month Math Beyond School Outreach Activities Teacher's Bulletin Board Canadian Mathematical Society University of Regina PIMS