 |
|
|
|
|
|
|
|
|
A triangular pyramid |
2007-07-22 |
|
From shani:
my homework question is confusing (yr 7 beginner)
"How many vertices does a triangular pyramid have."
(Mum thinks all triangles are triangular& vertices are sides)
I want to be sure.
Answered by Penny Nom. |
|
|
|
|
|
|
f(x) = (x^4) - 4x^3 |
2007-07-22 |
|
From Michael:
I'm a student who needs your help. I hope you'll be able to answer my question.
Here it is: Given the function f(x)=(x^4)-4x^3, determine the intervals over which the function is increasing, decreasing or constant. Find all zeros of f(x) and indicate any relative minimum and maximum values of the function.
Any help would be appreciated. Thank you for your time.
Answered by Harley Weston. |
|
|
|
|
|
|
Why are these two questions different? |
2007-07-21 |
|
From Mac:
Basically i like to know the difference between two solutions.
( I taken this questions from a web link)
Questions1) From 6 boys and 4 girls, 5 are to be selected to admission for a particular
house. In how many ways can this be done if there must be exactly 2 girls.
sol)
C(4,2)= 6
C(6,3)= 20
solutions is : 6*20= 120.
Question2) Out of 10 consonants and 4 vowels how many words can be formed each
containing 6 consonants and 3 vowels.
sol) C(10,6)
C(4,3)
and then 9! for arranging the selected words(9 character word).
solution= C(10,6) * C(4,3) * 9! = 30,48,19,200
Now my question is, why are we multiplying 9! in the second problem
and why we didnt multiply 5! in the first question ?
Answered by Claude Tardif and Harley Weston. |
|
|
|
|
|
|
The bearings of a ship's journey |
2007-07-20 |
|
From sugar:
A ship starts from point osail eastward for 6 hours. Then changes its course to N50E for 8 hours and then N62W for 10 hours until it reaches the point c. If the speed of the ship was imi/h, what is the bearing of the side oc?
Answered by Harley Weston. |
|
|
|
|
|
|
Some trig problems |
2007-07-20 |
|
From Jocelyn:
I wasn't able to solve this equation:
only find the function using Pythagorean theorem
Please help me....
sinA = 3/4 find secB
tanA = 3/4 find cosA
sinB = 4/5 find tan A
cosA = 5 find csc A
b =5; a= 12 find sin A
c =25; a = 24 find cot A
a = 6; c =10 find b?
Find B when c = 25; a = 24
Find A when a = 5 and b = 12
csc = 1/2 find cos
Answered by Penny Nom. |
|
|
|
|
|
|
Markup |
2007-07-19 |
|
From Andrea:
if a product cost $2.00 and it is marked up to $6.00 this would be a 200% increase.
(4/2 x100) = 200%. this is easy to compute.......but when you compute 2 x 200% it is 4.
this works if you only go up to 100% like $2 to $4 is 100% either way you compute it.
Why does it only work up to 100%
Answered by Penny Nom. |
|
|
|
|
|
|
A football stand |
2007-07-19 |
|
From jean:
a football stand 150 yd. long has 20 tiers of seats; each has a rise of 2 ft. and tread of 3 ft. it constructed of reinforced concrete with a cross section of 36*54. find the amount of material used in its construction.
Answered by Harley Weston. |
|
|
|
|
|
|
The volume of a cistern |
2007-07-19 |
|
From sharon:
We have a cistern to hold spring water that measures 12 feet in depth by 5 feet in diameter. How much in liquid gallons will it hold?
Answered by Penny Nom. |
|
|
|
|
|
|
A triangular trough |
2007-07-19 |
|
From janine:
A trough is formed by nailing together, edge to edge, two boards 11 ft. in length, so that the right section is a right triangle. If a 15 gallon of water are poured into the trough and if the trough is held level so that a right section of water is an isosceles right triangle, how deep is the water? (231cu.in=1 gal.)
Answered by Penny Nom. |
|
|
|
|
|
|
An oblique triangle |
2007-07-19 |
|
From fhay:
In an oblique triangle, If side a=95, side b=102 and side c = 150 find the missing angles solved by right angles...Thank's a lot......
Answered by Penny Nom. |
|
|
|
|
|
|
Je suis le plus petit entier de 3 chiffres. Qui suis-je? |
2007-07-18 |
|
From Auerhaan:
De quel chiffre parle-t-on?
Je suis le plus petit entier de 3 chiffres
Qui suis-je?
Le cahier de vacances donne comme solution : 120, ce qui me parrais très étrange !)
Merci d'avance pour votre réponse..!
Answered by Claude Tardif. |
|
|
|
|
|
|
A matrix of polynomials |
2007-07-18 |
|
From Mac:
can you please help me out to solve this ?
Let A be a n*n matrix, the elements of which are real (or complex) polynomial in x.
If r rows of the determinant becomes identical when x=a, then the determinant
A) has a factor of order r
B) has a factor or order > r
C) has no factor
D) has a factor of order < r
Answered by Harley Weston. |
|
|
|
|
|
|
How many diagonals does a polygon have? |
2007-07-18 |
|
From Edna:
how do you find the numbers of diagonals of a polygons?
Answered by Stephen La Rocque. |
|
|
|
|
|
|
I need all the possible 4 digit combinations... |
2007-07-18 |
|
From Jo:
I have lost the code for my car stereo. I need all the possible 4 digit combinations using the numerals 1 2 3 4 5 and 6. Thank you
Answered by Penny Nom. |
|
|
|
|
|
|
If x = 2 then 4 + 5x / 4 + x = ? |
2007-07-18 |
|
From Daniel:
If x = 2 then 4 + 5x / 4 + x = ?
Answered by Stephen La Rocque. |
|
|
