27 items are filed under this topic.
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Simplify 1/2^i |
2018-01-28 |
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From Deepak: How do I simplify this complex equation:
z=1/(2^i) Answered by Penny Nom. |
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Euler's polyhedron formula |
2016-05-20 |
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From Antonia: why does not cylinders follow Euler's polyhedron formula ( V-E+F=2) ??
if a cylinder has 3 faces, 2 edges and 0 vertices it doesn't follow Euler's formula??? Answered by Penny Nom. |
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We have 2 teams of 6 couples each that play 6 games |
2013-01-25 |
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From Denise: We put together a game night where we have 2 teams of 6 couples each that play 6 games. We haven't been able to figure out an arrangement that allows each couple to play each game with a different couple from the opposite team (i.e. Team A couples play every game with a different couple from Team B). Is this possible? It works with 2 teams of 5 couples each. Answered by Chris Fisher. |
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I started with Euler's identity and manipulated it |
2011-11-14 |
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From anonymous: I started with Euler's identity and manipulated it
e^i*pi=-1
e^-i*pi=(-1)^-1
e^-i*pi=-1
e^-i*i*pi=(-1)^i
e^--pi=(-1)^i
e^pi=(-1)^i
type it in in a calculator and you get e^pi=23.1406926... and
(-1)^i=0.0432139183... What did I do wrong? Answered by Robert Dawson. |
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A mythical soccer ball |
2011-10-27 |
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From Joel: We've been working on this problem diligently and can't seem to come up with the answer book's answer. We think it may be wrong, yet want to check it with an expert. Here goes.
The school's new soccer balls are covered with 64 regular hexagonal panels. Each hexagon measures 2 inches between opposite corners and 1.5 inches between opposite sides. What is the total surface area of the soccer ball? Answered by Robert Dawson and Lorraine Dame. |
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Vertices and sides of a polygon |
2011-03-04 |
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From RINA: My questions is : would a vertices and sides of a polygon be the same number. For example, a octagon it has 8 points and 8 sides. Am i correct? Answered by Robert Dawson. |
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i^i |
2010-11-21 |
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From trale: Can we use e^ix=cosx+isinx for finding i^i like that: x= pi/2 =>
e^(ipi/2)=0+i then [e^(ipi/2)]^i=i^i.then we find i^i= 0,207879576....
is it true? can we give value for x for free?thank you. Answered by Harley Weston. |
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Faces, edges and vertices |
2009-02-04 |
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From sheila: what is the relationship between the number of faces and the number of edges of a triangular pyramid ? Answered by Penny Nom. |
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The 2 rightmost digits |
2008-12-18 |
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From Peter: Is there a pattern for the 2 rightmost digits of a power? For example, one problem for a math competition was what are the 2 rightmost digits of 3^1993? Answered by Robert Dawson and Victoria West. |
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I have 6 vertices and 10 edges |
2008-10-20 |
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From Jacquelin: I have 6 vertices and 10 edges. One of my faces is a regular polygon. Answered by Chris Fisher. |
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An Euler diagram and a logic argument |
2008-09-18 |
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From Regina: Use a Euler diagram to determine whether the following argument is valid or invalid.
No wizard can yodel
All lizards can yodel
No wizard is a lizard Answered by Penny Nom. |
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A shape |
2008-04-03 |
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From Joshua: what shape has 4 faces, 4 corners and 9 edges. Answered by Penny Nom. |
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Which solid figure has 4 more edges than vertices? |
2007-03-22 |
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From dawn: which solid figure has 4 more edges than vertices? Answered by Penny Nom. |
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What constitutes a face for a geometric solid? |
2007-02-14 |
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From Erica: What constitutes a face for a geometric solid? We have been getting conflicting answers from different textbooks. Some teachers are saying that cylinders and cones do not have faces. I'm thinking that cylinders have 2 and cones have 1. Please enlighten me. Thanks! Answered by Walter Whiteley. |
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Is there a solid shape with 5 faces, 8 edges, and 4 vertices? |
2006-02-11 |
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From Annie: Is there a solid shape with 5 faces, 8 edges, and 4 vertices? Answered by Penny Nom. |
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A problem with sets |
2004-01-20 |
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From Jason:
Given that the universal set S is the set of all sports fans, and
F={x|x is a football fan}
B={x|x is a basketball fan}
H={x|x is a hockey fan}
a)Describe (F^B)' (f intersect b)' in words
b)Draw a Venn Diagram and shade the region that represents the set of football fans or both basketball and hockey fans.
Answered by Penny Nom. |
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I have three circles... |
2003-01-30 |
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From Tony: I HAVE THREE CIRCLE THAT IS CIRCLE TOGETHER: IN CIRCLE A, THE NUMBERS ARE: 11 I KNOW IS IN CIRCLE A, BUT I HAVE THE: 5 THAT IN A AND C, I HAVE THE 2 IN THE CIRCLE C AND B AND AND A, THE CIRCLE C I KNOW THAT 10 IS IN THE CIRCLE THE 4 IN CIRCLE A: AND B: IN CIRCLE B, I KNOW NUMBER 13 IS IN CIRCLE B; BUT I HAVE THE 3 IN CIRCLE B AND C AND I HAVE THE 2 IN CIRCLE B AND C AND A ,THE 4 IN CIRCLE B AND A. HOW DO I FIND THE SUM IN CIRCLE C AND IN B IN BOTH CIRCLE A AND B AND B AND C NOT IN CIRCLE B, AND NOT CIRCLE C. Answered by Penny Nom. |
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Collinear Points |
2003-01-13 |
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From Gary:
Which of the 4 points are collinear when you construct the following concurrent lines or rays of a triangle? - P(1), the point where the angle bisectors intersect.
- P(2), the point where the altitudes (or extensions) intersect (inside or outside of the triangle).
- P(3), the point where the medians intersect.
- P(4), the point where the perpendicular bisectors (or extensions) of the three sides of a triangle intersect.
This is for my 9-12 high school class in geometry. My name is Gary Thanks for your help. Gary
Answered by Harley Weston and Chris Fisher. |
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Baseball, basketball and football |
2002-10-08 |
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From Debbie: The school newspaper is interviewing 6th grade students to see what sports they follow regularly on TV. Of the 70 students interviewed; 40 enjoyed basketball; 40 enjoyed baseball; 40 enjoyed football; 20 enjoyed basketball and football; 22 enjoyed baseball and basketball; 27 enjoyed football and baseball; and 12 enjoyed all three sports. How many students out of the 70 interviewed didn't follow any one of the three sports? Answered by Leeanne Boehm, Penny Nom and Walter Whiteley. |
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Conditional probability |
2002-05-19 |
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From Manny: In a certain school, it is known that 80% of the students use the internet for school projects, 60% use e-mail on a regular basis, and 90% use the internet for school projects or for e-mail on a regular basis. a student from this school is selected at random Determine thge probability that the student used e-mail, given that the student used the internet for school projects. ANS: how can i solve this question by useing the vin diaagram Answered by Andrei Volodin. |
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A health club |
2001-11-25 |
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From Maria: A health club with a membership of 650 people operates a running track and an indoor swimming pool. A survey of the membership indicates that 68% use the running track, 44% use the swimming pool, and 8% use neither. If a member is chosen at random, what is the prbability that the member uses: a) Both the track and the pool? b) Only the track? Answered by Penny Nom. |
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Faces |
2001-02-21 |
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From Sandy: How many faces are there on a sphere? What are the faces of a cone? What is the definition of a "face" of a 3D object? Answered by Walter Whiteley. |
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Euler's Formula |
2000-11-11 |
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From Denise Roberts: I'm trying to design a unit (possibly involving a Webquest) on Polyhedra and I cannot find a formula I once used. The formula involved the number of vertices (V), edges (E), and faces (F) of the polyhedra. Answered by Walter Whiteley. |
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2^32 + 1 |
2000-04-08 |
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From Un Etudiant: 232 +1 can be divided by 641 , why? Answered by Claude Tradif. |
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Lunes |
1999-02-04 |
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From Kai G. Gauer: A prof once told me that a certain type of lune is quadrable given that the diameter is an integer. She used the construction of a right isosceles triangle within a semicircle and later constructed another semicircle on the base of the first semicircle and used area subtraction to show equality to a smaller triangle with quadrable area. What happens when the original inscribed triangle is no longer isosceles? She mentioned something about other lunes also being quadrable; but not all. What are the dimensions of other such lunes? Note: I'm not certain if I still have my hercules account; please simply post on Q&Q. Thanks! Answered by Chris Fisher. |
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Complex numbers and the quadratic formula |
1998-12-25 |
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From Richard Peter: My age is 16, and my name is Richard. My question relates to the topic complex numbers & the quadratic formula. I would like to know how to solve quadratic equations in which the discriminant is less than 0 (i.e. we get two complex solutions to the quadratic) 3x2+2x+5 = 0 and how mathematicians like euler contributed to this field. If it would be possible I would also like to know how this type of quadratic equations can be graphed? Answered by Harley Weston. |
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The two-digit numbers from 10-99 |
1998-01-21 |
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From Alexis Riddle: My name is Alexis. I'm a student in 8th grade and I'm taking Algebra I Honors. My question is: In a string of numbers, two adjacent digits are considered as a two-digit number. For instance, the string 11012 contains the numbers 10, 11, and 12. What is the number of digits in the smallest string that contains all of the two-digit numbers from 10-99? Please help and thank you for any assistance you can give me. Answered by Penny Nom. |
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