Triangle Definition and 1000 Threads

Homework Statement In a ##\Delta ABC##, angle A is greater than angle B. If the measures of A and B satisfy the equation ##3\sin x-4\sin^3 x-0.75=0##, then angle C is equal to A)##\pi/3## B)##\pi/2## C)##2\pi/3## D)##5\pi/6## Homework Equations The Attempt at a Solution The...

Let ABC is an acute angled triangle with orthocentre H. D, E, F are feet of perpendicular from A, B, C on opposite sides. Let R is circumradius of ΔABC. Given AH.BH.CH = 3 and (AH)2 + (BH)2 + (CH)2 = 7, answer the following Q1. \frac{\prod \cos A}{\sum \cos^{2}A}Q2. What is the value of R...

Hello! I got a problem wrong and I'm trying to figure out what happened. it's triangle ABC bisected by line BD Given line BD is the perpendicular bisector of line AC, Prove line BD bisects angle ABC I got Step 1 Line BD is the perpendicular bisector of line AC Reason: Given Step 2 Line D is...

I recently discovered that for a 3rd degree polynomial I was studying, f(5) - 4f(4) + 6f(3) - 4f(2) + f(1) = 0. At first I just though it was coincidental that the coefficients were the 5th row of Pascal's Triangle, but then I tried a 2nd degree polynomial and found that f(4) - 3f(3) + 3f(2) -...

A, a'...a''? im in the process of typing out an idea I had about triangles, and I wanted some input, but I ran into a problem when I realized I do not know how to denote multiple "prime" angles. In this diagram, I am working with the corners of a triangle, but have extended the rays outwards...

I have found a way to find right triangles using only one side. How do I show you without being deleted?

Someone please help me with this question. I can't do and I have a calculus exam in the morning.

Homework Statement See attachment Homework Equations The Attempt at a Solution If the y-coordinate of the center of mass is given by (1/A)*∫y dA, how come the solution uses bh/2 as the area? This triangle isn't right angled so that area formula should not hold. What am I missing?

Homework Statement Question is attached. I know there's a few ways to solve this, but I'm wondering specifically why my integral of F ds isn't working. Homework Equations F = k * q^2 / r^2 U = ∫ F ds cos 30 = √3/2 s= rcos30 The Attempt at a Solution U = 2 * cos 30 * k *...

Here is the question: http://i259.photobucket.com/albums/hh299/the-real-guitar-hero/Capture_zpsf2b9cd28.png part A = 3√5 b=y=2X+1 c=(0,1) D is where I am confused. Area of triangle = (base x height)/2 from working out, line 2 cuts the x-axis at -1/2. line 1 cuts the x at 7. the height is 3...

In an orthogonal cordinate system determine the area of the triangle with vertices in (-4,1), (1,4) and (-5,10) There is prob many way to solve it so go ahead with your method:) I made a hint for vector method. Hint

considering the set of triangles, whose sides are the x and y axes, and the tangents to the curve e^{-5x}, x>0 to estimate the maximum area of such a triangle can be. I have no progress, well I know area is \frac{x*y}{2}.

We know that in triangle ABC angle A equals \alpha and side a=\frac{b+c}{2}. How to find angles B and C knowing that B\geqslant C? For which values of \alpha the problem has solutions? ps. a, b, c are only notations. answer. \frac{\pi-\alpha}{2}\pm\arccos(2\sin\frac{\alpha}{2})

Homework Statement See attached image Homework Equations 1/4πε*q/r The Attempt at a Solution I know that since the problem gives centimeters, there are initial changes to units to be made in the permittivity constant. This makes it 8.86x10^-9 N/nanoCoulombs and 100 mm. But...

For the vectors in the figure, with a = 1.1 and b = 2.6, what are (a) the z component of a x b, (b) the z component of a x c, and (c) the z component of b x c? Everything I've tried to look up involves vectors that are in unit notation, etc. I just don't understand how to do it when all you...

I blieve the mid point in space of arbitrary triangle formed by points A,B,C is the point at which the line A -> midpoint(B,C) B -> midpoint (A,C) C ->midpoint (A,B) meet (i also think C is redundant, that where A to mid and B to mid cross is basically the mid point of the whole...

Let ABC be a triangle such that \frac{BC}{AB-BC}=\frac{AB+BC}{AC}. Determine the ratio \frac{\angle A}{\angle C}.

Homework Statement There are three point masses. 1 is fixed in space with the 2nd point mass directly below it on the ground. The 3rd point mass is an unknown distance to the right of mass number 2. These 3 point masses for a rt triangle with point 2 at the 90 degree angle. The vertical...

Homework Statement Hello I'm learning Fourier transforms via the Stanford lecture series on Youtube. In the 6th lecture, the professor claims that the FT of a triangle function is the square of the sinc function. I'm trying to derive this, but I can't get my math to work out. Could someone...

Homework Statement B=magnetic flux density . A is the vector potential of magnetic field. How to get the formula B=∇A Homework Equations http://en.wikipedia.org/wiki/Magnetic_moment The Attempt at a Solution B=magnetic flux density . A is the vector potential of magnetic field...

Homework Statement y=x^2 y=1 Find the volume of the bounded region using an equilateral triangle cross section Homework Equations c^2=a^2+b^2 The Attempt at a Solution I'm will solve it with respect to x 1st. 2∫((1-x^2)h)/2 dx from 0 to 1 base=2(1-x^2) (2-2x^2)^2=(1-x^2)^2+h^2 4-8 x^2+4...

Homework Statement Consider the points A(1,2) B(-2,-1) and C(3,-2) on the Cartesian plane. 1. Find the length of the segments AB and BC 2. Find the angle of the triangle at the vertex B Homework Equations Cosθ=(AB*BC)/|AB| |BC| ? The Attempt at a Solution The length of the...

1. ∫1/(x2 + 36)dx 2. I started by trying a trig substitution. The normal form, "a2 + x2, x=(a)tan(θ)," I thought could be reversed here: x2 + 62 x = 6tan(θ) dx= 6sec2θdθ ∫1/[(6tanθ)2 + 36] = ∫1/[36(tan2θ + 1)]*6sec2θdθ = ∫1/[36sec2θ]*6sec2θdθ = ∫1/6dθ = (1/6)θ + C...

Homework Statement prove that sin^2(a)=sin^2(b)+sin^2(c) if and only if ABC is a right triangle in A i worked really hard on this one I'm really confused why i didn' get the answer Homework Equations The Attempt at a Solution a+b+c=pi tried turning everythng to cos 2x didn't helpi...

http://https://www.physicsforums.com/attachment.php?attachmentid=56297&stc=1&d=1362318192 problem:- The situation is shown in attachment. the right angled frame of rods (in stationary ) is moving at speed v perpendicular to its hypotenuse. according to length contraction the corresponding...

Hello. I have an example for you. I'm curious how. Yesterday I was on the mathematical competition. One example I can not solve. I want to know how. Can you help me, please? Consider a convex polygon of 1415 sides, which circumference is 2001 cm. Prove that between its peaks, there are 3 such...

Let a, b, c be the lengths of the sides of a triangle. Prove that: $\sqrt{a+b-c}$+$\sqrt{b+c-a}$+$\sqrt{c+a-b}\leq\sqrt{a}+\sqrt{b}+\sqrt{c}$

Homework Statement Suppose that the magnitude of the net electrostatic force exerted on the point charge q2 in the figure is 0.65 N . (Figure 1) http://imgur.com/4lZliPq Find the distance D. q1 = 2.1 micro C q2 = 6.3 micro C q3 = -.89 micro C Homework Equations F = k |q1|...

Homework Statement Let pascal(n,i) be the value of the ith element of the nth row of Pascal's triangle. Using induction show that the number of unique paths from entry {0,0} to entry {n,i} in Pascal's triangle is equal to pascal(n,i). The Attempt at a Solution The base case n=1 seems easy...

Homework Statement The first problem is as follows And the second one is Homework Equations For the first question, I do not really know what equations to use. I tried writing it out in the form Z1 = a + ib, Z2 = c + id, etc, but that got me nowhere. The second question has been...

Homework Statement What is the area of a right triangle whose inscribed circle has radius 3 and whose circumscribed circle has a radius 8? Homework Equations The diameter must be the hypotenuse of the circle The Attempt at a Solution The answer is 57, but I do not know the...

Problem: Let A, B, C be three non-collinear points. Let D, E, F be points on the respective interiors of segments BC, AC and AB. Let θ, φ and ψ be the measures of the respective angles ∠BFC, ∠CDA and ∠AEB. Prove IAS(ABC) < θ +φ + ψ < 540 - IAS(ABC).(IAS means internal angle sum). Now I am...

Find the electric potential at point P in the figure. http://i.imgur.com/8FNSoML.png V = kq / r So what I did was calculated the electric potential each force gives on the point P. Vp1 = (8.99e^9) (2.75e^-6) / .625 Vp2 = (8.99e^9)(-1.72e^6) / .625 Vp3 = (8.99e^9) (7.45e^6) /...

Is it possible that a triangle with angles totaling over 180 degrees could exist without being embedded in a 3rd dimension?

Hi, I'm still practicing how to find volume. 1. My problem is this: "Find the volume of the solid described below: The base of the solid is the disk x^2 + y^2 ≤ 4. The cross-sections by planes perpendicular to the y-axis between y=-2 and y=2 are isosceles right triangles with one leg in the...

Homework Statement Find a formula for the sum of the elements of the nth row of Pascal's Triangle Homework Equations C(n,r) = [C(n-1,r-1) + C(n-1,r)] C(n,0) = C(n,n) = 1 The Attempt at a Solution I started with the summation of the elements in the rows n \sum^{n}_{r=0} C(n,r)...

EDIT: My guess to the below question is that no you can't triangulate a triangle because a legitimate triangulation each edge can only be linked up to exactly two distinct faces, so if you just have one triangle, each edge would be linked up to one face (the face of the triangle) I'm really...

Hello, I have been given a homework problem and I don't want any help on solving the problem, (I'm not even going to post the problem - I want to figure it out myself), I only want to understand what the problem is asking. (That's why I've posted in this section rather than the homework...

Okay, I tried to draw a picture of the graph the word problem is talking about. This is a bad picture, but it was the best my computer could take! :/ 1. Les triangles dangereux is an 80-minute movie showing nothing but a slowly growing triangle. It got a strong reception at Cannes...

Hey guys, I hope someone can give me some pointers with this because it should be really easy but I am just not getting it! I want to show that for a triangle inscribedin a circle an equilateral traingle gives the maximal perimeter. I've tried a few things and just get bogged down in algebra...

Hi, I should Show the following: D is subset of R^2 with the triangle (0,0),(1,0),(0,1). g is steady. Integral_D g(x+y) dL^2(x,y)=Integral_0^1 g(t)*t*dt my ansatz: Integral_0^1(Integral_0^(1-x) g(x+y) dy) dx With Substitution t=x+y Integral_0^1(Integral_x^1 g(t) dt) dx...

Suppose we have 3 points in the plane given by: $\displaystyle (x_1,y_1),\,(x_2,y_2),\,(x_3,y_3)$ and we wish to find the area of the triangle whose vertices are at these points. We may let the base b of the triangle be the line segment between the first two points, and the altitude h of the...

Homework Statement hi i have a photo with some given information. I need to find the length of all three sides of that triangle and also the area of the triangle I have already found them but i get 2 different results Homework Equations I have used both cosinus and pythagoras...

Homework Statement let ABC be a triangle where I divides angle BAC(angle A) => BAI=IAC Prove that I is the centroid of (B,AC)and (C,AB) Homework Equations i think phitagors wil come in handy but don't know how to use it The Attempt at a Solution let ac = a and AB = b aIB+bIC=0 (vectors)...

I have this triangle and I know just the two sides indicated there. How can I find angle theta? I tried decomposing the triangle in two right triangles and using trigonometry find one side, but I can't figure how to do that using just the hypotenuse

Good day, while reading up on an elementary math study book, i have encountered that a proof is build upon the following (see attachment for the figure). Are the Areas CDE and BED really the same? I tried to calculate this from abstraction, not sure where I could have made a mistake.. g1 is the...

Homework Statement Three positive charges, A, B and C, of 3 × 10-6, 2 × 10-6, and 3 × 10-6 Coulombs respectively, are located at the corners of an equilateral triangle of side 0.2 meters. Find the magnitude in Newtons/Coulomb of the electric field at the center of the triangle...

a, b, and c are unit vectors and a+b+c=0. This is the first part of a question and the solution involves the fact that a, b, and c form a triangle. I am having a really hard time how these vectors form a triangle. Can you pleases be as thorough as possible in your answer. Thank you so much for...

Homework Statement Let C be the oriented triangle lying in the plane 2x+y+z=4. Evaluate ∫ _{C} F*dr where F(x,y,z)=y2i + z - xk. Homework Equations I will be using ∫C∫curl F \bullet \vec{n} to solve this problem. But when I'm trying to find \vec{n} using -gxi - gyj + k, I get Using...

Homework Statement area of triangle with a base of: 2 & 3/4 and a height of 4/9 Homework Equations 1/2 * (b*h) The Attempt at a Solution i used: 1/2*(11/4 * 4/9) = 44/72 = 22/36 = 11/18