# I need to that if there is better way to prove the following: I am trying to prove that x r = k and k is a multiple of x only when x is prime. I said that if x

3,237 results
1. ## RESEARCH REPORT

HI I WOULD LIKE TO KNOW WHAT I CAN POSSIBLY PROVE ABOUT EITHER THE BERMUDA TRIANGLE OR ATLANTIS THE LOST EMPIRE WE AARE SUPPOSED TO PROVE SUMTHIN ABOUT EITHER OF THOSE TWO CHOICES.... I ALSO NEED SITES THAT CAN HELP ME PROVE SOMETHING ABOUT THEM

asked by TRIXIE on April 6, 2008
2. ## math

My math teacher wants us to prove that all of our answers are correct. But how am I supposed to be able to prove stuff, like this, for example. The directions want you to write out the words in to an equation. Seven is the sum of X and 5. so my answer is

asked by john on October 13, 2009
3. ## math

Prove that if A is a diagonalizable matrix, then the rank of A is the number of nonzero eigenvalues of A. http://ltcconline.net/greenl/courses/203/MatrixOnVectors/symmetricMatrices.htm I've read the entire page and while it's on the correct topic, it

asked by mathstudent on January 19, 2007
4. ## math

Let f:A->B, where A and B are nonempty, and let T1 and T2 be subsets of B. a.Prove that f^-1(T1 U T2)= f^-1(T1) U f^-1(T2). b.Prove that f^-1(T1 intersects T2) = f^-1(T1) intersects f^-1(T2). I think once I see a I can do b. c. Prove that f^-1(T1) -

asked by dreww1961 on October 14, 2010
5. ## Geometry

Can you just help me with this thanks Directions: Tell which property is being used for each step I will give you an example Example: prove that if 4x-8=-8 then x=0 Given: 4x-8=-8 Prove: 0 A. 4x-8=-8 Given B. 4x-0 Addition property C. x=0 Division property

asked by Terrie on September 15, 2009
6. ## history

I'm supposed to prove that if america stopped getting involved in the affairs of the world the result would NOT be chaos. PLEASE HELP WITH ANY IDEAS ON HOW TO DO SO! It is not possible to prove a hypothetical. Can you prove that if Tinkerbelle stopped

asked by ally on November 28, 2006
7. ## Science - Proof of Propositional Logics

I am being asked if I can prove P, L, Q? (without using resolution-refutation). Propositional clauses: 1. P -> V 2. !P -> (!V and F) 3. (V or F) -> Q 4. Q -> L From here I was able, with resolution-refutation, to determine that we cannot prove P but we

asked by Jack on February 10, 2008
8. ## Math

Find inverse of f if f(x)= x^2-4x+3, (for x is smaller than and equal to 2). First prove that f(x) is one to one in the defined domain of f and then obtain the inverse function. I know how to find the inverse. We just switch x and y. so y=x^2-4x+3 becomes

asked by Mahnoor on January 20, 2015
9. ## Math Proof

Prove: Let a,b exist in the reals with a

asked by Ashley on September 15, 2014
10. ## geometry

prove that every every line segment has one and only one end point . use euclids geometry to prove

asked by dipti on July 25, 2013
11. ## Geometry

Given: UR=VW Prove: UV=RW(Midpoint) Given: angleABE=angleDBC(Bisectors) Prove: angleABD=angleCBE

asked by Troy on October 12, 2010
12. ## Math

Prove :cosx-cosy= -2sin(x+y/2)sin(x-y/2) Prove: 2cot-2tanx= 4-2sec^2x / tanx

asked by Sarah on November 23, 2010
13. ## maths

If the sum of the squares of the roots of the quadratic equation ax^2 + bx + c = 0 is m:n, prove that b^2= 2ac + 4a^2 I really have no idea how to prove it so pls help

14. ## calculus

Prove that there is a number that is exactly one more than its cube. (don’t solve just show there is one) Prove that the function f(x)= cosx-x has a zero in (o. pi/2) Justify.

asked by kelli on September 24, 2010
15. ## Physic

From equation x= A sin wt, prove that the acceleration of SHM is a= -w^2x w is omega actually.. 2.using relationship between velocity, v and displacement, x prove that v=w(A^2-x^2)^1/2

asked by Syam on September 4, 2014
16. ## math

Given: ; CE=CA ,EB AND AD are medians Prove: EB=AD 2.)Write a paragraph proof. Given: AC bisects

asked by Anonymous on May 12, 2011
17. ## Advanced Maths (Vectors) AQA Level

Triangle ABC with D, E and F the midpoints of BC, AC, and AB. G is the midpoint of AD such that the ratio AG:GD =2:1, VECtors AB =p and BC =q Prove that B, G and E are collinear. prove the same results for point C, G and G

asked by Jat on February 12, 2012
18. ## Math, Inequalities

Prove the following inequalities. Then state for which values the LHS equals RHS. 1) a^2 + b^2 ≥ 2(a-b-1) 2) Given a + b = 1, prove the inequality a^2 + b^2 ≥ 1/2 Please explain how you solved it. Thanks.

asked by Anne on May 25, 2017
19. ## Advanced Maths (Vectors) AQA Level

Triangle ABC with D, E and F the midpoints of BC, AC, and AB. G is the midpoint of AD such that the ratio AG:GD =2:1, VECtors AB =p and BC =q Prove that B, G and E are collinear. prove the same results for point C, G and F

asked by Jat on February 12, 2012
20. ## math

Use the Generalized PMI to prove: 2^n > n^2, for all n > 4 First of all, it's true for n=5. Then to prove it for n+1... Assume 2^n > n^2. Then 2^(n+1) = 2*2^n > 2*n^2 > 2*(4n) since n>4 => n^2>4n I'm stuck there.

asked by Pat on March 3, 2011
21. ## linear algebra

1)If A is an invertible matrix and k is a positive integer, then (A^k)^-1 = (A^-1)^k note: ^ stand for power, -1 stand for inverse of A 2)If A is an invertible matrix, then (transpose of A)^-1 =transpose of(A^-1) 3)Prove A^2 = A, then I - 2A = (I - 2A)^-1

asked by soasi piutau on April 13, 2012
22. ## Math

Suppose line GH is congruent to line JK, line HE is congruent to line KL, and angle 1 is congruent to angle L. Can you prove that triangle GHI is congrunet to triangke JKL, abd if so, how? A. You can use SAS to prove the triangles are congruent. B. You can

asked by Bettey on October 8, 2018
23. ## history

i need to think of a thesis statement to prove aboutamerican history i am thinking about going toward something about talking about george washington any suggestions? or if you have any other really good topics that i could prove please post! thanks

asked by calilh on September 1, 2008
24. ## Math

Use mathematical induction to prove that 5^(n) - 1 is divisible by four for all natural numbers n. Hint: if a number is divisible by 4, then it has a factor of 4. also, -1 = -5 +4 This is a take home test so I don't want the answer because I want to know

asked by Help on May 12, 2010
25. ## ordered fields

prove (3x^2 + 4x-1)/(7x^5+5)>0 is field. can you just prove one of the addition axioms?

asked by julia on November 30, 2011
26. ## Very easy math

my teacher told me that the inverse of addition was subtraction and that the inverse of subtraction was addition... could you prove it to me -x = (-1)x ((-1)x)^-1 I don't see how I'm suppose to get + x by taking the inverse of -x i've always been told in

asked by Very easy Math on September 2, 2009
27. ## College Math : Linear Algebra

Suppose A is a square matrix satisfying the equation A^3 - 2I = 0. Prove that A and (A - I) respectively are invertible. (the hint is to find an explicit equation for A^-1. To prove A is invertible, this is what I did although I don't that it's right: A^3

asked by David on February 9, 2010
28. ## Math - Mathematical Induction

3. Prove by induction that∑_(r=1)^n▒〖r(r+4)=1/6 n(n+1)(2n+13)〗. 5. It is given that u_1=1 and u_(n+1)=3u_n+2n-2 where n is a positive integer. Prove, by induction, that u_n=3^n/2-n+1/2. 14. The rth term of a sequence is given by

asked by Iman on April 17, 2012
29. ## Geometry

Given quadrilateral ABCD,ABllDC, diagonal AC. we can prove that angle 1= angle 2, but cannot prove angle 3=angle4 Why is this. What must be true about the sides of the Quadrilateral in order to prove that angle 3 is congruent to angle 4? My answer: The

asked by DANIELLE on February 27, 2007
30. ## Geometry

Given quadrilateral ABCD,ABllDC, diagonal AC. we can prove that angle 1= angle 2, but cannot prove angle 3=angle4 Why is this. What must be true about the sides of the Quadrilateral in order to prove that angle 3 is congruent to angle 4? My answer: The

asked by DANIELLE on March 5, 2007
31. ## Calculus

1. Prove that (f(x+h)-f(x-h))/2=f'(x) 2. Prove that any parabola sastifies the equation (f(x+h)-f(x-h))/2=f'(x) For the first question, I tried to solve it but there is an extra h tacked on to one side. I have no clue what to do for the second question.

asked by Andre on February 2, 2016
32. ## Math

1) Prove that for every x>=0 and 0

asked by david on January 7, 2015
33. ## math

Do a two column proof. Given: HI=FG Prove: GH>FI If FGI is a triangle,and GIH is a triangle, and they both share a common side, GI, and FIH is a straight line, how do you prove the answer?

asked by Ryan on December 18, 2012
34. ## Biology

The body of multicellular animals (salamanders, frogs and so on) is made of more than hundred different kinds of somatic cells. Even though they’re so different, they all have the same genome (the same DNA, the same set of genes). This is called genomic

asked by S on April 12, 2013
35. ## Geometry

If x is the midpoint of line vy and wz And the prove is triangle vwx is congruent triangle yzx can you help me solve this using two column prove

asked by Anonymous on December 5, 2013
36. ## Algebra

If x is the midpoint of line vy and wz And the prove is triangle vwx is congruent triangle yzx can you help me solve this using two column prove

asked by Anonymous on December 6, 2013
37. ## Algebra NEED HELP PLEASE

If x is the midpoint of line vy and wz And the prove is triangle vwx is congruent triangle yzx can you help me solve this using two column prove

asked by Anonymous on December 6, 2013
38. ## Math

let f: ℤ→ ℤ and g: ℤ → ℤ be functions defined by f(x) = 3x + 1 and g(x) = |_x/2_|. (a) Is f o g one-to-one? prove (b) is f o g unto? prove (c) Is g o f one-to-one? (d) Is g o f unto? Thank you for your help.

asked by Anonymous on August 12, 2014
39. ## Geometry

Given a triangle ABC with A(6b,6c) B(0,0) and C (6a,0), prove that the medians of the triangle are concurrent at a point that is two thirds of the way from any vertex to the midpoint of the opposite side. I'm not sure how to prove this. I tried and when I

asked by Cecilia on October 24, 2013
40. ## Geometry: Ms. Sue or Steve or someone help please?

Given a triangle ABC with A(6b,6c) B(0,0) and C (6a,0), prove that the medians of the triangle are concurrent at a point that is two thirds of the way from any vertex to the midpoint of the opposite side. I'm not sure how to prove this. I tried and when I

asked by Cecilia on October 24, 2013
41. ## Math

I have math HW and these are the questions i wasn't aware of how to answer... please help. a)Prove that 4x-y-1=0 is parallel to y=4x-5 b)Show that the points A(3,1), B(5,2) and C(11,5) are collinear c)Show that the lines y=2x-4 and x+2y-10=0 are

asked by Crissy on September 17, 2011
42. ## Math

Proove that: a)2^(1/2) is not rational. b) prove that 2^(1/3) is not rational. I have managed to prove the first part, but i am stuck on the second can someone give me an hint please?

asked by arthur on February 1, 2015
43. ## math

1. Let f : Z to Z and g : Z to Z be functions de fined by f (x) = 3x + 1 and g(x) = [x/2] . (a) Is fog one-to-one? Prove your answer. (b) Is fog onto? Prove your answer. (c) Is gof one-to-one? Prove your answer. (d) Is gof onto? Prove your answer.

asked by Denial on August 12, 2014
44. ## math

Prove the identity: cos^4(x)-sin^4(x)=1-2sin^2(x).with explanation im confused on this one cause of the 4th power of the sine. does this mean that we put it in the calculator 4 times? and what exactly does it mean by prove the identity- does it mean like

asked by Anonymous on April 15, 2012
45. ## Movies and physics

Hello...I need to find a modern day movie that has at least three or more physics mistakes. I need to prove they are mistakes...as well, is Zeno's Paradox a credited/valid source to use to prove something such as the everlasting gobstopper, from Willy

asked by Physics! on December 20, 2007
46. ## A physics problem

Hello...I need to find a modern day movie that has at least three or more physics mistakes. I need to prove they are mistakes...as well, is Zeno's Paradox a credited/valid source to use to prove something such as the everlasting gobstopper, from Willy

asked by Physics! on December 20, 2007
47. ## Math- Geometry Proofs

What are some ways to prove that a triange is isoscles? i have to make a two column proof based on a problem. What is the exact problem I need help with my geometry homework. We are doing proofs and i need some help because proofs are really hard!! def.

asked by Jenny on November 22, 2006
48. ## calculus

A) How do you prove that if 0(

asked by Sarita on April 2, 2010
49. ## Calculus

A) How do you prove that if 0(

asked by Sarita on April 2, 2010
50. ## calculus

A) How do you prove that if 0(

asked by Sarita on April 3, 2010
51. ## Discrete Math

Use mathematical induction to prove the truth of each of the following assertions for all n ≥1. 5^2n – 2^5n is divisible by 7 If n = 1, then 5^2(1) - 2^5(1) = -7, which is divisible by 7. For the inductive case, assume k ≥ 1, and the result is true

asked by Francesca on March 23, 2011
52. ## Maths

X and Y are points on the sides BC and AC of a triangle ABC respectively such that angle AXC = angle BYC and BX = XY. Prove that AX bisects the angle BAC. I believe the first step is to prove ABXY is a cyclic quadrilateral. Unfortunately, I don't know

asked by Bobby on July 21, 2008
53. ## Mathematics

mathematically, how to prove we cant divide by zero. and why multiplication of zero with any number leads to zero itself . can we mathematically prove that

asked by JOHNTHAN on April 26, 2017
54. ## geometry

i have triangle inequalities. how do i prove them?? i have a figure and i have to prove an angle is bigger than another angle

asked by Anonymous on April 2, 2008
55. ## Algebra proof

Prove that if w,z are complex numbers such that |w|=|z|=1 and wz\=-1, then w+z/1+wz is a real number I so far i have determined that w and z both have to equal less than one, but i cannot figure out how to prove this. if wz does not equal one it must mean

asked by Gem on March 31, 2015
56. ## Calculus

limit of (x*(y-1)^2*cosx)/(x^2+2(y-1)^2) as (x,y)->(0,1). By evaluating along different paths this limit often goes to 0. This does not necessarily imply that it exists. So how would i prove that it exists. Can someone please show me how i can prove using

asked by Jim on April 11, 2016
57. ## math

Let f:ℤ+ → ℤ+ be the function defined by: for each x ∈ ℤ+, f(x) is the number of positive divisors of x. - find integers m, n, nd k so tha f(m)=3, f(n) = 4 anf f(k) = 5 -is f one-to one? Explain, is f unto? prove is it true that all positive odd

asked by excel on March 20, 2014
58. ## math

Prove the following identities: a) (cosec θ + cotθ)(cosecθ - cotθ) = cotθtanθ b) 2/(1 + sinθ) + 1/(1- sinθ) = (3sec^2)θ - tanθcosecθ I basically just have to prove Left HandSide = Right Hand Side

asked by Proving Identities Question (Trig.) on July 18, 2008
59. ## discrete math

Let f:ℤ+ → ℤ+ be the function defined by: for each x ∈ ℤ+, f(x) is the number of positive divisors of x. - find integers m, n, nd k so tha f(m)=3, f(n) = 4 anf f(k) = 5 -is f one-to one? Explain, is f unto? prove is it true that all positive odd

asked by excel on March 20, 2014

Let f:ℤ+ → ℤ+ be the function defined by: for each x ∈ ℤ+, f(x) is the number of positive divisors of x. - find integers m, n, and k so tha f(m)=3, f(n) = 4 anf f(k) = 5 -is f one-to one? Explain, is f unto? prove is it true that all positive odd

asked by excel on March 21, 2014
61. ## Vectors

I have a test on monday and I need help with these two questions, please. 1)Prove that the magnitude of the vector OP = (a,b,c) is given by |OP| = sqrt a^2+b^2+c^2 I understand how to find the magnitude, but I don't know how to prove it. 2)Give a

asked by Anonymous on March 29, 2008
62. ## History

What was the reason Columbus sailed to the Americans? He wanted to find riches He wanted to prove that the world was round He wanted to prove his seamanship •• He wanted to see India

asked by Lily on August 30, 2016
63. ## elementary differential geometry

Suppose that all the tangent lines of a regular plane curve pass through some ﬁxed point. Prove that the curve is part of a straight line. Prove the same result if all the normal lines are parallel.

asked by thida on January 31, 2015
64. ## Computer proof

Prove by induction on all positive integer k that if m is any ordinary nfa with k states, and m has fewer than k - 1 transitions, then there exists a state of m that is not reachable. Let N be the λ-NFA: "L" for "λ" b >(1) -----> ((2)) | ^. | b| | L. | a

asked by Steve on May 9, 2013
65. ## Calculus

If the function f is defined by f(x)=0 if x is rational f(x)=1 if x is irrational prove that lim x-->0 f(x) does not exist. Can someone help me answer this question step by step so I would know how to prove a question like this next time? Thank you.

asked by Anonymous on September 20, 2015
66. ## algebra..Matrix...math

Hi, Please help me to this question would prove less than 10 hours Athens has a population of n ,m club with any club membership is an even number and the number of members of both clubs to prove and show m

asked by ali on May 28, 2015
67. ## Calculus

a) prove that the function x^3 + 9x^2 +33x assumes the value -8 at least once b)using the mean value theorom or rolle's theorom - no other methods will be accepted - prove carefully that x^3 + 9x^2 + 33x takes on the value -8 at most once

asked by David on December 10, 2009
68. ## Trigonometry desperate help, clueless girl here

2. solve cos 2x-3sin x cos 2x=0 for the principal values to two decimal places. 3. solve tan^2 + tan x-1= 0 for the principal values to two decimal places. 4. Prove that tan^2(x) -1 + cos^2(x) = tan^2(x) sin^2 (x). 5.Prove that tan(x) sin(x) + cos(x)=

asked by Suzy on August 17, 2013
69. ## Trignometry

Can you please help me prove that ((1-cosx)/(1+cosx))=(cscx-cotx)^2? I can only do work on one side to prove that its end result is equal to the other side.

70. ## Math Proof:

Let a,b exist in the reals with a

asked by Ashley on September 16, 2014
71. ## Math Geometry

Geometry Question: Prove the symmetric Property for congruence of triangles. Given: ∆ABC≅ ∆DEF Prove: ∆DEF≅ ∆ABC

asked by Reigel on May 18, 2011
72. ## DISCRETE MATHS

Prove that for every set S, Ø \subseteq( S. i need to Use vacuous proof. i know that vacuous proof is when the hypothesis is always False. but for this i find it very difficult please can you help me prove this? thanks.

asked by Anonymous on August 28, 2013
73. ## Maths

Please help with these questions: (please show how to do) 1. How many differently shaped rectangles, with positive integer dimensions, have a perimeter equal to their area? 2. Let x be any number less than one, and let y be any number greater than one. S=

asked by Mea C on February 3, 2010
74. ## MATH (SURDS)

we have been asked to prove that it is possible to determine the value of a surd using either similar figures or Pythagoreans theorem. we have been shown how to construct the surd using a compass and ruler. but we now have to prove that our method is

asked by Frank on April 23, 2008
75. ## IB HL Math

I need to that if there is better way to prove the following: I am trying to prove that x r = k and k is a multiple of x only when x is prime. I said that if x is non-prime, then: Let a = 6 Let r = 4 6! (6 – 4)! 4! = 3(2) x 5 x 4! (2!) 4! = 15 It is not

76. ## geometry

Prove that the angle bisectors of the base of the isosceles angles of the isosceles triangle are congruent using statement and reason proof i dont really now how to prove this problem but i now what a transversal is and the angles of a trashes line. can u

asked by maria on December 9, 2016
77. ## algebra 2

Please show how to do these problems so i understand. 1)Prove that sin^2 x (1+cot^2 x)=1 2)Prove that tan x (cot x+tan x)=sec^2 x

asked by Janet on August 11, 2015
78. ## algebra 2

Please show how to do these problems so i understand. 1)Prove that sin^2 x (1+cot^2 x)=1 2)Prove that tan x (cot x+tan x)=sec^2 x

asked by Janet on August 11, 2015
79. ## math

I need to prove my answer is correct, the directions say to simplify the problem, one problem was 2a + 10a I got 12a. how could I prove that it's correct, if i can?

asked by john on October 14, 2009
80. ## geometry

Prove that a triangle with sides : x^2-1, 2x, and x^2 +1 is a right triangle. i substituted the "x"s with 2 and got 5, 4, and 3 and i said that because of the common pythagorean triplets this triangle is a right trianlg is there another way to prove this

asked by Ashley on September 14, 2017
81. ## physics

how to prove prove m = m0 / sqrt(1 - v^2/c^2)?

asked by Marinho on October 21, 2009

Prove that 2sinxsiny = cos(x-y) - cos(x+y) Prove that sin2x + sin2y = 2sin(x+y)cos(x-y)

asked by ariza on November 5, 2009
83. ## math

Given: ∠TRS = ∠URS ∠TSR = ∠USR Based on the given information and the algebraic and geometric properties presented or proven thus far, choose the congruence theorem that could be used to prove the triangles congruent. If it is not possible to prove

asked by nay on April 28, 2017
84. ## Math - Discrete math

1). Let G be the statement: " for all real numbers a and b, if a -|_a_| < 1/2 and b - |_b_| < 1/2 then |_a + b_| = |_a_| + |_b_|" (the symbol is for the FLOOR of a and b) A. is G true? prove it b. state wether the CONVERSE, CONTRAPOSITIVE AND NEGATION ARE

asked by excel on February 7, 2014
85. ## number theory

How do you prove that any palindrome, a number that reads the same backwards and forwards, with an even number of digits is divisible by 11? I know how to show a number is divisible by 11, but how do you prove the above case?

asked by Laura on April 19, 2009
86. ## calculus

prove that 5x - 7 - sin3x = 0 has at least one zero and prove that it has exactly one real zero. How am I supposed to show my work for this? I don't really understand how to show my work for the IVT. Without that I can't do any work for the MVT.

asked by Rob on December 16, 2011
87. ## geometry honors

Can you prove ABCD is a parallelogram based on the given information? Explain. Given: x = 5, y = 4 Prove: ABCD is a parallelogram. The image consists of a quadrilatera ABCD with their sides AB, BC, CD, DA as 3x + 12, 7y - 8, 6x - 3 and 5y respectively.

asked by jacky on January 9, 2015
88. ## Math

1a) Prove that there exist irrational numbers a and b so that a^b is rational. look at the numbers √2^√2 and (√2^√2)^√2 1b) use similar idea to prove that there exists a rational number a and an irrational number b so that a^b is irrational 1c)

asked by excel on February 18, 2014
89. ## Geometry- how to write proof

ABC is a right triangle. Angle C is 90 degree. Altitude CD is drawn to hypotenuse AB. Prove AB/BC = BC/BD and AB/AC = AC/AD This is a theorem. How do I prove it? Thanks. Dont you have similar triangles? You can show this by looking at the angles

asked by Jen on February 23, 2007
90. ## MHS

Given: MC bisects both ∠ACB and side AB. Based on the given information and the algebraic and geometric properties presented or proven thus far, choose the congruence theorem that could be used to prove the triangles congruent. If it is not possible to

asked by Peez on March 11, 2014
91. ## trigo math

7. Prove that tan B sin B + cos B = sec B. 11. Prove that tanλ cos^2λ +sin^2λ/sinλ = cos λ + sin λ. 12. Prove that 1+tanθ/1+tanθ = sec^2θ+2tanθ/ 1-tan^2θ. 21. Prove that sin^2w-cos^2w/ tan w sin w + cos w tan w = cos w – cot w cos w.

asked by RUDY on December 13, 2012
92. ## Math- any help would be greatly appreciated

In triangle ABC, the medians AD,BE, and CF concur at the centroid G. (a) Prove that AD < (AB + AC)/2. (b) Let P=AB+AC+BC be the perimeter of triangle ABC. Prove that 3P/4 < AD + BE + CF < P.

asked by Stephanie on May 19, 2016
93. ## math

Is there a way to prove this in upwards of 5 steps? Apparently there is?? Prove. 2^n + 2^n = 2^(n+1) I posted this before however apparently I need something more indepth in terms of the # of steps.

asked by Joshua on March 18, 2013
94. ## Math

In triangle ABC, the medians AD,BE, and CF concur at the centroid G. (a) Prove that AD < (AB + AC)/2. (b) Let P=AB+AC+BC be the perimeter of triangle ABC. Prove that 3P/4 < AD + BE + CF < P.

asked by Stephanie on May 19, 2016
95. ## Math

a) prove the identity: Ax(BXC)=B(A*C)-C(A*B) A,B,C vectors x- cross product *-dot product b) use part a) to prove that cross product is not associative.

asked by larry on October 31, 2014
96. ## math(geometry)

prove Given: line r is parallel to line s prove:

asked by kim on October 5, 2007
97. ## math

prove the following: given: ABCD is a trapezoid with bases BC and AD to prove: BX • AX = DX • CX X is the intersection of the segment going from BD and AC i need the answer in a two column proof statements Reasons 1. ABCD is a trapezoid with 1. given

asked by bob on April 28, 2010
98. ## math analysis

also i don't understand this problem. i need help and to prove....the symbol ⊂ is subset. here the problem: Prove that There exist an open interval B = (c,d), and sets A and C, with B ⊂ C, and a function f: A-->C such that f^(-1)(B) is not an open

asked by Vylette on October 22, 2013
99. ## discrete math

Let A= {for all m that's an element of the integers | m=3k+7 for some k that's an element of positive integers}. Prove that A is countably infiite. Note: you must define a function from Z+ to A, and then prove that the function you definied is a bijection

asked by Samantha on December 4, 2010
100. ## Elementary Euclidean Geometry(Math)

Little Joseph once said: I was once asked to prove that (PROOF ONE) in a right triangle, the sum of the squares of two sides equals the square of the third. Smart little rascal that I am, I proved it with ease. I was then asked to prove that (PROOF 2) if

asked by Dav on September 2, 2015