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Sigma notation 2019-12-04
From Kenneth:

What would be used for the top and bottom indices for the sigma sign in my example shown below?
If the amounts were 1 + 2 + 3, the top index would be 3 and the bottom would be i = 1, but if the amounts are 1 + 2 + 4, or 1 + 0.05 + 1/3, what would the indices be since these amounts are in an uneven pattern.

I thank you for your reply and explanation

Answered by Harley Weston.
(3d) Whether line segment intersects triangle 2019-04-13
From rj:
Well hello,

Lets say I have a triangle,

Not any ordinary triangle, but a triangle that is represented in 3 dimensions. I also have a line segment.

Lets say that this triangle has points A(0,0,0), B(1,0,0), C(0,1,1)

And the line segment has points D(0,1/2,0), E(1,1/2,1)

In what way can I find if the line segment and triangle intersect? Their intersection point?

I don't prefer matrices, because they don't make any sense, but ... if that's the only way to solve this, then do what's necessary.

Thank you in advance.

Answered by Penny Nom.
The volume of a slab 2017-01-21
From Russell:
Working with a segment of a circle. The O.D. is 3.440" the length of the chord is 3.130 I need information on the volume of the largest area. I would like to know (in thousands of an inch) how tall would the largest area need to be to equal .1143 cubic inches If you need more info I can send it Thanks in advance
Answered by p.
A line segment of length root 5 2014-12-15
From angela:
On the dot grid below, draw and label a line segment with length square root 5 the dot grid is 8 by 10
Answered by Penny Nom.
Forming a triangle from 3 line segments 2012-03-15
From rustom:
A point X is selected at random from a line segment AB with midpoint 0. Find the probability that the line segments AX, XB, and A0 can form a triangle.
Answered by Penny Nom.
Augmented matrix 2011-12-14
From Britney:
Write Augmented matrix and use row reduction to solve.
I need major help with this problem! Tomorrow is my semester test and I have no idea how to do this.

Answered by Robert Dawson.
Two line segments in the plane 2011-08-15
From Tim:
For this problem I actually have tried to visualise the image in my head many times. This question makes my head spin.

Four points lie in a plane. They are partitioned into two pairs so that the sum of the lengths of the segments joining the points of each pair has the minimal possible value. Prove that these segments have no common points.

Answered by Chris Fisher.
Line segments 2011-01-04
From Izsak:
What is the formula to find the number of segments that can be named by a given number of points on a line?
Answered by Penny Nom.
Can a line segment curve over two planes? 2010-02-14
From Graham:
I am working on a math fair project. Can a line segment curve over two planes? Such as, if I had a three dimensional L bracket and I drew a line segment on it with a marker starting on the bottom of the L and had it curve around the corner and up the top, would it still be considered one line segment? Or is that two line segments? Is there a rule that a line segment can only occupy one plane? Thank you. Graham
Answered by Chris Fisher.
Segments of a ring gasket 2009-09-20
From Robert:
I am in the process of making an Excel spreadsheet in which our sales team just needs to enter the outside diameter, inside diameter, and number of segments to price ring gaskets that are too big to fit on a sheet of material and need to be cut into segments. With your help I was able to create a spread sheet that can calculate the Chord lengths, and Segment height on a single gasket segment. I am now stuck trying to come up with a formula to figure out the height of the second segment when it is stacked on the first segment, then use it to add more depending on the quantity of segments needed. I have an illustration below showing 2 segments (of a gasket that was segmented into 4 pieces) stacked together. I need to find a formula to get the dimension from "A" to "B".
Answered by Harley Weston.
2+6+12+20+30+42 2009-04-24
From fredy:
what is the sigma notation for the series 2+6+12+20+30+42?
Answered by Stephen La Rocque.
A plane cuts a line segment 2009-03-17
From Manis:
Find the ratio in which the line joining (2,4,16) and (3,5,-4) is divided by the plane 2x-3y+z+6=0.
Answered by Robert Dawson.
A linear system 2009-03-13
From Rasanga:
Use the row echelon form of the augmented matrix to solve the following linear system.

Answered by Harley Weston.
Augmented matrix: independent, dependent, or inconsistent? 2009-02-23
From Anna:
Perform row operations on the augmented matrix as far as necessary to determine whether the system is independent, dependent, or inconsistent.

x + y + z = 11
x - y + 3z = 5
2x + 2y + 2z = 15

Answered by Harley Weston.
Congruent line segments 2009-02-05
From casie:
marica drew one-line segment on a graph with endpoint of (0,9) and (0,4). she drew another line segment with endpoints (1,1) and (6,1). are the line segment congruent?explain
Answered by Penny Nom.
Segments of a sphere 2009-01-16
From Herman:
How do I solve for a segment of a sphere so that the orange peel or pie shaped section is converted to a flat surface with dimensions. I form large diameter domes, elliptical and sphere heads on a press. I enter the diameter say 30 feet with two segments above and below the equator and the total number of segment around the circumference at say 18 so the widest part of the pie shaped section will fit my press. How do I take the upper or lower course above or below the equator and figure the height of the orange peel shape, the chord length at top and bottom, and solve for the right angle at 2 degree increments down the arc length of the pieces so I can layout the flat plates prior to pressing. Thanks for your help.
Answered by Robert Dawson.
Converting grams to milliliters 2009-01-04
From Faiza:
I was looking for how to convert grams into mL and I read on this site to convert one to the other you need to know what substance you are measuring. so if I am measuring sugar or any of the baking ingredient like flour how do I convert them from grams to mL is there a simple method I can use to do that?
Answered by Penny Nom.
The midpoint o a line segment 2008-11-15
From Jane:
The vertices of a triangle are at (1,7), (6,-1) and (0,3). Find the coordinates of the midpoints of the sides.
Answered by Penny Nom.
Using the augmented matrix 2008-10-17
From Karlena:
I am supposed to write the augmented matrix of the system and use the matrix method to solve the system. I must show my work algebraically


Answered by Harley Weston.
A linear system 2008-08-23
From dipesh:
consider the system of equations
by reducing the augm matrix to row echelon form, find the solution to the equation.

leaving the first two equations the third is changed to -3x+6y+14z=-31 show the equations have infinitely many solutions and give a general formula for them

Answered by Penny Nom.
The midpoints of the sides of a quadrilateral 2008-07-22
From JOEL:
Answered by Penny Nom.
A reflected line segment 2008-07-14
From Peter:
Segment AB has endpoints A(-1,2) and (3,1). Segment AB is reflected over the y-axis such that A becomes A' and B becomes B'. What is the positive difference between the lengths of segment AA' and segment BB'?
Answered by Janice Cotcher.
A large concrete shape 2008-01-16
From Keith:
what is the cubic yards of an area that is not a perfect 1/4 circle? The dimensions are 100ft. x 60ft. x 125ft. curcumferal arch x 3ft. depth?
Answered by Stephen La Rocque.
Sigma notation 2008-01-06
From jamelia:
what is this word problem in sigma style i am so lost at this point my first time ever attempting this subject 1+2+3+4+5
Answered by Penny Nom.
Animals for sale 2007-12-09
From Marion:
This question has come up and I know the answer and the equation, but how do you solve this?
Please share the proof. cows=$10, pigs=$3, chickens=$.50
In any combination buy 100 animals with $100.

Answered by Leeanne Boehm.
An augmented matrix 2007-11-29
From Beth:
I am having troubles fiinding this augnmented matrix. I know how to do it but everytime i do it it get a different answer and its not the right answer. Could you help me to make sure I do it right?

Here is the problem:
4x - 3y = 5
2x +9y = 6

Answered by Harley Weston.
Dividing a segment into 3 congruent parts 2007-10-30
From Carolyn:
I am doing construction. I have a line segment drawn. I need to divide a segment into 3 congruent part. How do I do that?
Answered by Penny Nom.
Segments on a line 2007-09-10
From Cathy:
This question was on my daughter's geometry assignment. Write a general rule of formula for finding the number of segments that can be named by a given number of points on a line. For example, 2 points on a line = 1 line segment; 3 points on a line = 3 segments; 5 points on a line = 10 segments.
Answered by Penny Nom.
Standard Deviation 2007-06-13
From Adrian:
If you are told that the mean salary of a certain group of workers is $30,000 with a standard deviation of $4000, what proportion of workers earn over $38,000? What proportion of workers earn less than $18,000? Assume the distribution of wages is normal.
Answered by Stephen La Rocque.
Water tank volume 2007-05-29
From Cecelia:
Answered by Stephen La Rocque.
An augmented matrix 2007-02-13
From Mary:
I've been trying for quite some time now to figure this out. I have to solve this by using the Gauss-Jordan Method: 3x - y = 15 2x + 3y = 10 Can anyone help me?
Answered by Penny Nom and Gabriel Potter.
Line segments on dot paper 2007-01-21
From Khaori:
The three line segments below are drawn on centimeter dot paper.

a. Find the length of each segment to the nearest ten-thousandth of a centimeter.
b. Could these line segments be arranged to form a triangle? If no, explain why or why not. If yes, answer this question: could they form a right triangle? Explain why or why not.

Answered by Penny Nom.
Sigma notation 2006-12-05
From Marie:
how do i get this in sigma notation...i only need an explanation 1^2 + (2+3)^2 + (4+5+6)^2 + (7+8+9+10)^2....
Answered by Penny Nom.
How many line segments are necessary? 2006-10-04
From Varun:
If you place 35 points on a piece of paper so that no three are collinear, how many line segments are necessary to connect each point to all the others?
Answered by Stephen La Rocque.
The area of part of a circle 2006-05-29
From Larry:
need to find area of a circle between a given line (cord) to the circumference of the circle (see attachment). I often review blue prints of homes and many times have to know the area the home.
Answered by Stephen La Rocque and Penny Nom.
A line segment connecting two vertices of a polygon 2005-02-02
From James:
What is a line segment (not a side) connecting two vertices of a polygon called?
Answered by Penny Nom.
The radius of a circle 2004-08-24
From Peter:
If you slice any circle with a line, and call the distance of the line between intersections the "y" length and the perpendicular length to the shorter side of the curve the "x" length, what is the resulting equation for the radius?
Answered by Penny Nom.
Row echelon form 2004-07-24
From Michael:
My name is Michael and I'm in the 11th grade. I have a Math question that I can't solve. The problem is system of equations that I need to do in augmented matrix form, find the row echelon form, and solve it by using back substitution.

2x + 3y + 7z =13
3x + 2y - 5z = -22
5x+ 7y - 3z = -28

Answered by Penny Nom.
Augmented matrix 2002-12-31
From Michelle:
I am trying to augment a matrix so that i can find the values of the variables a, b, and c. For the life of me i can't find a solution to the matrix: 3 -5 2 ' 22 2 3 -1 ' -9 4 3 3 ' 1 I thank you for your help, Michelle
Answered by Penny Nom.
An augmented matrix 2002-04-20
From A student:
Hi my math teacher asked us to solve an augmented matrix. I am in twelfth grade and need help. The book we are working on is college algebra. Here it is


Answered by Penny Nom.
Sigma 2001-03-31
From A student:
What does the Sigma symbol mean in mathematics?
Answered by Penny Nom.
Partitioning of an arbitrary line segment 2001-02-08
From David:
Did Euclid's Geometry include a construction for the regular partitioning of an arbitrary line segment?
Answered by Chris Fisher.
A system of equations in five unknowns 2000-03-20
From Will:
I have been having some problem with the following question for some time. I would appreciate any help on solving the problem or a solution.

Q: Assume that a system of equations in the unknowns x1, x2, x3, x4 and x5 when converted to row echelon form gives


Answered by Penny Nom.
Énigme 2008-04-06
From Frédérique:
Tu es dans une pièce ou il y a 3 interrupteurs reliés a 3 lumières dans une autre pièce que tu ne vois pas.Comment fais-tu pour savoir a quelle lumière chacun des interrupteurs est relié si tu ne peux aller voir dans l'autre pièce qu'une seule fois!Merci a l'avance!!!
Answered by Claude Tardif.
Le terme suivants 2008-03-30
From jacques:
voici 2 suites. Explique la logique qui permet de passer d'un terme a l'autre dans chacune des suites et trouve le terme suivants. 1)douze,5,trente,6,neuf,4,seize,... no.2) 26,vx,18,dt,36,tx,51,...
Answered by Maxime Fortier Bourque.
La longueur des segments formant un triangle 1999-10-05
From Michel Provencher:
Connaissant la longueur des segments formant un triangle,comment détermine-t-on chacun de ses angles si:
  1. il S'agit d'un triangle rectangle

    Sachant que la somme des angles d'un triangle est de 180 degrés et sachant par conséquant qu'un des angle est de 90 degrés (triangle rectangle) il reste donc, 90 degrés à partager entre les 2 angles restant. Si les 2 segments formant l'angle droit sont de même longueur on obtient un angle de 45 degrés pour les angles restant soit 1/2 angle droit ce qui ne me pose évidement aucun problème. Quel relation, S'il y en a une, y a t-il entre la longueur de ces 2 segments et les angles restants.

  2. il S'agit d'un triangle quelconque

Answered by Claude Tardif.



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