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29 items are filed under this topic.
Points on the x-axis 2015-03-14
From Justin:
jamie tells her friend that ordered pairs that have an x-coordinate of O line x-axis. She used the origin as an example. Describe Janine error. Use a counterexample to explain why Janine statement is false
Answered by Penny Nom.
A region described by inequalities in cylindrical coordinates 2015-02-21
From Rahul:
I am not able to visualize a solid given by inequalities as under (in cylindrical coordinate system) 0= I know that (can visualize) first 2 inequalities say it is a cylinder of infinite length. It seems that third inequality poses the restriction to the height as well as it makes us to remove a cone.
But I just can not understand it clearly.
Thanks in advance!

Answered by Penny Nom.
Equal ordinate and abscissa 2013-08-15
From sonit:
the slope of tangent to the curve y=(4-x^2)^1/2 at the point, where the ordinate and abscissa are equal, is
Answered by Penny Nom.
r=10cos(t) in cylindrical coordinates 2013-05-18
From r.m:
question from calculus exam: what is the figure obtained having eqn.r=10cos(t) in cylinderical coordinates? i know it is a cylinder with center (5,0) ,but can't the equation represent two cylinders ,one with center (5,0) and the other with center (-5,0). thanks for any help.
Answered by Penny Nom.
Polar coordinates 2010-04-14
From Lan:
Given the rectangular equation (x^2)+2x+(y^2)+y=0, find the polar equation.
Answered by Harley Weston.
Integration of cos (x^2+y^2) dx dy 2010-02-12
From anna:
How do you evaluate the integration of integration of cos (x^2+y^2) dx dy?
Answered by Tyler Wood.
The line through D(-4, 0) and E(2, 6) 2009-11-16
From Rogerson:
The point F is on the line through D(-4, 0) and E(2, 6) so that DF=4DE. Find the coordinates of F.
Answered by Penny Nom.
A side of a rectangle 2009-07-15
From hanbal:
Could please help solving this problem

A(1,3) and D(5,5) are two vertices of a rectangle ABCD. The equation of line AC is 3y=4x + 5
a) the equation of line DC

Answered by Chris Fisher.
Subdividing a four-sided lot 2009-03-27
From kannan:
i have a 1.5 acre land having four sides
A-B=64.8 meters
B-C=94.2 meters
C-D=54.4 meters
D-A=127.2 meters
angle at D is 90
the side AB (frontage)is road facing i want to split the plot in to two halves having same almost area and almost equal frontage, kindly help me, if possible explain with drawing.


Answered by Harley Weston.
Cutting a pipe at an arbitrary angle 2008-09-20
From John:
from the original question Al asked about cutting a 200 diameter pipe in 45 degrees. can someone explain the math steps required to creating the graph. I am trying to do the same thing only using a 150 degree cut.
Answered by Harley Weston.
Vectors and an orientation change in the axes 2008-08-30
From moumita:
what differences take place to a vector because of choice of orientation of the coordinate axes and why??
Answered by Harley Weston.
A regular hexagon 2008-05-20
From Martin:
Given a regular hexagon with center on the origin of an x-y plane with coordinate (r,0) on the x axis, we are to express the coordinates of "A" located at 120 deg from (r,0) in terms of "r".
Answered by Janice Cotcher.
Three points on the circumference of a circle 2007-07-30
From Bharathi:
given a circle with radius r and a point x,y on its circumference,output two other points x1,y1 and x2,y2 on the circle so thar all 3 points form a equilateral triangle.
Answered by Stephen La Rocque.
What is the equation? 2006-09-13
From A parent:
Answered by Penny Nom.
Plotting co-ordinates on a number plane 2006-09-08
From Victor:
I need to plot co-ordinates (0,2), (2,-2), (-2,0), and (0,0) on a number or co-ordinates plane, I am not sure how to do this, and get lost after the first point, can you please help?
Answered by Penny Nom.
Polar to Cartesian coordinates 2006-01-15
From Linden:
How do you convert six units at 30 degrees Polar Coordinate into a Cartesian Coordinate?
Answered by Penny Nom.
Converting coordinates 2004-10-25
From Allen:
I am trying to help my son with his home, but I don't remember these conversions. Please help.

1. Convert the following coordinates Cartesian x = 7, y = -24

2. Convert the following coordinates Polar r = 4, theta = pi / 3

Answered by Penny Nom.
Terminology 2003-08-31
From Maria:
My daughter Veronica is a rising 6th grader and has to complete some Summer Math
assignments and would like to ask you three questions:
  1. ___________ are number pairs that have a product of 1.

  2. You can name any point on a plane with two numbers. These two numbers are called _____________.

  3. A _______________ is the size of a cube that is exactly 1 inch on each edge.

Answered by Penny Nom.
A triangle in the complex plane 2003-07-10
From Scott:
The vertices O and A of an EQUILATERAL triangle OAB in the complex plane are located at the origin and 3 + 3i. Find all possible values for the complex number representing the vertex B. Give the location of B in both polar and cartesian form (to 2.d.p)
Answered by Penny Nom.
Transformations of pattern blocks 2003-02-06
From Cheryl:
I am trying to help my 8th grade son with Transformations - use of patttern blocks. He has to trace a figure and reflect it across the x-axis, which I can do, but then it indicates include ordered pairs - that confuses me.
Answered by Penny Nom.
Counterclockwise 2001-09-14
From Rolanda:
When Descartes invented the coordinate system he decided to number them counter-clockwise. Why?
Answered by Chris Fisher.
Polar coordinates 2000-02-24
From Tran Trung:
How do I convert r = 2/(2sin(theta) - 3cos(theta)) to rectangular and x2 + y2 -2y = 0 to polar form?
Answered by Harley Weston.
A valentines project 2000-02-21
From Courtney Dohoney:
I was assigned a valentines project. Our job is to make a valentines card that has a math theme. On my valentines card I would like to include the set of equations that when graphed look like a heart. If you can figure out a set of equations and get it back to me I would be very happy.
Answered by Harley Weston.
A Polar Plot 1999-05-06
From Irene:
Consider the polar equation r=2-3Cos(theta/2) In the interval [o, 4Pi], how would you find the area of one of the leaves and also the length of one of the edges of a leaf?
Answered by Harley Weston.
Complex numbers/polar coordinates 1999-03-25
From Kate Cegelis:
What is the relationship between complex numbers and polar coordinates?
Answered by Harley Weston.
Intersection of planes 1998-11-22
From Dave Rasmussen:
I am a teacher of secondary mathematics with a question about the uses of Three Dimensional Co-ordinate Geometry. I have been teaching my students to write equations of planes and lines, - to find the intersection of these and the distance between them. What I am having difficulty finding are good applications of these techniques to "real world" situations. Can anybody help me?
Answered by Walter Whiteley and Harley Weston.
Calculating the Intersection Point. 1997-12-10
From Milton Parsons:
Given 2 lines through (x1,y1),(x2,y2),and (x3,y3),(x4,y4). Can you give me a good formula for calculating the intersection point. I would greatly appreciate it.Thanks.
Answered by Chris Fisher and Penny Nom.
A Geometry Problem 1997-09-18
From Rebecca Henry:
A circle is centered at the vertex of the right angle of an isosceles triangle. The cirlce passes through both trisection points of the hypotenuse of the triangle. If the length of a radius of the circle is 10, find the area of the triangle.
Answered by Chris Fisher Harley Weston.
Y-axis 1997-05-29
From Leah:
I know that the proper name for the X axis is the abscissa, but, what is the proper name for the Y axis?
Answered by Chris Fisher.



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