Wednesday

April 16, 2014

April 16, 2014

Total # Posts: 79

**SCIENCE,PHYSICS**

3 is the answer Ohh brilliant cheateres rockzzz Calvin shokzzz Plz tell other answers to public

**geometry**

ABC is a triangle with AC=139 and BC=178. Points D and E are the midpoints of BC and ACrespectively. Given that AD and BE are perpendicular to each other, what is the length of AB?

**statics**

A bag contains 4 balls, each of which have a positive integer written on it. Let X be the random variable of the value written on a single ball drawn from the bucket. If E[X]=8, what is the maximum possible value of E[X^2]?

**geometry (help steve)**

A circle of radius 1 is drawn in the plane. Four non-overlapping circles each of radius 1, are drawn (externally) tangential to the original circle. An angle γis chosen uniformly at random in the interval [0,2π). The probability that a half ray drawn from t...

**physics**

An airplane of a certain density and shape flies at a constant speed. To do so, it must fly with a certain velocity v0. If the size of the airplane is scaled up in length, width, and height by a factor of two, it can only fly above a new velocity v1. What is v1/...

**physics**

Consider a horizontal road with such a set of traffic lights, each spaced 100 m apart. A car sits at the first traffic light. At t=0 the light turns green and the car accelerates. What is the maximum time t in secondsthe next light must turn ...

**physics**

P1/t1=p2/t2

**physics**

Many of you may have noticed the phenomenon that basketballs get flat if the weather is cold. If a basketball was inflated to a gauge pressure of 60,000 Pa when the temperature outside was 20∘C, what is the gauge pressure inside the basketball&nb...

**math**

wrong 326

**Geometry**

Find the number of 6 -term strictly increasing geometric progressions, such that all terms are positive integers less than 1000.

**physics**

Two point charges +q=1 μC and −q=−1 μC with mass m=1 g are fixed at the positions ±r⃗ 0 with |r0|=1 m. The charges are released from rest at t=0. Find the time &#...

**physics**

Three identical conducting spheres are located at the vertices of an equilateral triangle ABC. Initially the charge the charge of the sphere at point A is qA=0and the spheres at B and C carry the same charge qB=qC=q. It is known that the sphere B exerts an elect...

**math**

He is correct only 1 integer satisfy he mean

**physics**

Lol brilliant cheaters wtf

**Geometry**

There are 100 runners, each given a distinct bib labeled 1 to 100. What is the most number of runners that we could arrange in a circle, such that the product of the numbers on the bibs of any 2 neighboring runners, is less than 1000?

**Maths**

yes it is 3

**Geometry**

What is a and what is b?

**Geometry**

If two six-sided dice are rolled, the probability that they both show the same number can be expressed as a b where a and b are coprime positive integers. What is the value of a+b ?

**Geometry(first one is typo)**

Let ƒÆ=sin −1 7/25 . Consider the sequence of values defined by a n =sin(nƒÆ) . They satisfy the recurrence relation a n+2 =k 1 a n+1 +k 0 a n ,n¸N for some (fixed) real numbers k 1 ,k 0 . The sum k 1 +k 0 can be written as p q , where p...

**Geometry**

Let ƒÆ=sin −1 7 25 . Consider the sequence of values defined by a n =sin(nƒÆ) . They satisfy the recurrence relation a n+2 =k 1 a n+1 +k 0 a n ,n¸N for some (fixed) real numbers k 1 ,k 0 . The sum k 1 +k 0 can be written as p q , where p...

**math**

ABC is a triangle with circumcenter O, obtuse angle BAC and AB<AC. M and N are the midpoints of BC and AO respectively. Let D be the intersection of MN with AC. If 2AD=(AB+AC), wh...

**Geometry**

Convex quadrilateral ABCD has sides AB=BC=21, CD=15 and AD=9. Given additionally that ∠ABC=60∘, what is the length of BD?

**Probability**

A school is running a raffle for two prizes. 59 tickets were sold for the raffle, numbered 1,…,59. All the tickets are put into a hat and a teacher picks out two tickets which have numbers i and j from the hat. What is the expected value of |i−j|?

**maths**

I got it till now maximize a+b, if Re (b)=-Im(a), Re (a)-21 <Im (b)<Re (a)-5 So find max a+b

**maths**

A group of 5 people are going to meet weekly at the library for 4 weeks. Each week, two people are selected at random to speak. Each person may speak in multiple weeks, but no pair of people will speak together more than once. The probability that there is a person who will ne...

**Physics**

The fundamental frequency of the G string of a guitar is f=196Hz. The fundamental vibrational mode of the string is described by the standing wavey(t,x)=acos(2πft)sin(πxL)where L=65cm is the length of the string and a=1mm is the amplitude of ...

**maths**

A group of 5 people are going to meet weekly at the library for 4 weeks. Each week, two people are selected at random to speak. Each person may speak in multiple weeks, but no pair of people will speak together more than once. The probability that there is a person who will ne...

**maths**

Find the number of different ordered quadruples (a,b,c,d) of complex numbers such that a^2=1 b^3=1 c^4=1 d^6=1 a+b+c+d=0

**maths**

thanks

**maths**

Find the largest possible value of x^3+y^3+z^3 for realx, y, z, such that xyz^2=−64y−128x x^2yz=−32y−32z 3xy^2z=128x−64z

**maths**

ABC is an acute triangle with ∠BCA=35∘. Denote the circumcenter of ABC as O and the orthocenter of ABC as H. If AO=AH, what is the value of ∠ABC(in degrees)?

**Algebra**

Strange r meets stranger

**Algebra**

As x ranges over all real values, what is the minimum value of f(x)=|x-123|+|x-456| + |x-789|

**Physics/math**

Can't get it, Didn't studied this topic, Would you please work the solution.

**Maths Probability**

When writing a math expression, any time there is an open bracket "(", it is eventually followed by a closed bracket ")". When we have a complicated expression, there may be several brackets nested amongst each other, such as in the expression (x+1)∗(...

**Trigonometry**

Every point (x,y) on the curve y=log(3x)/log2 is transferred to a new point by the following translation (x′,y′)=(x−m,y−n), where m and n are integers. The set of (x′,y′) form the curve y=log(12x−96)/log2. What is the value of m+n? Det...

**calculas**

At time t=0 s, the radius of a circle is equal to 15 cm. The radius of the circle increases at a rate of 0.5 cm/s. The rate of change of area at t=20 s is equal to mπ cm^2/s, where m is a positive integer. W...

**algebra**

Let no. of men be x No. of women = 5x + 2 Total students = No. of men + women 50=x + 5x+2 48=6x x=8 No. of women = 5x + 2 = 5 * 8 + 2 =42 (ans)

**Physics help ASAP please**

No direction no length of river how broad river is then how to find?

**Math**

700 $ make 42281 $ in ten years Totally wrong this cant be true He had invested money that will be get in a collection not in payment

**Math**

This Compound interest using Amount = principle * ((Rate + 100)/100)^time Here Rate is per time period i.e 8% per annum will be 2% per quater Time period is 10 years = 40 quater year P=700 $ Putting values Amount = 700 * ((2+100)/100)^40 =700 * (51/50)^40 using scientific calc...

**math**

30 + 20/((1*5)*2) since 1*5 = 5 and 5*2 = 10 this become 30 + 20/10 30+2 32

**math**

how

**math**

25 independent, fair coins are tossed in a row. What is the expected number of consecutive HH pairs? Details and assumptions If 6 coin tosses in a row give HHTHHH, the number of consecutive HH pairs is 3.

**Arithmetic**

B-1/2 Let no. of books be x No. of history books equal x into 1/3 I.e.x/3 No. Of English books equal x into 1/3 I.e. x/6 Rest books = no. Of science books =total books -(history books+English books) =×-(×/3 +×/6) =x-(3x/6) =x-x/2 =x/2 books are of science of ...

**Maths**

ABC is a right angled triangle with ∠ABC=90∘ and side lengths AB=24 and BC=7. A semicircle is inscribed in ABC, such that the diameter is on AC and it is tangent to AB and BC. If the radius of the semicircle is an improper fraction of the form a/b, where a and b ar...

**Trigonometry**

Suppose N = xyzyx, where x is nonzero but y and z could be any digit. Then there are 9(10^2) = 900 possible palindromes to consider. Recall that a number is divisible by 4 iff its last two digits are divisible by 4. Thus, if N is divisible by 4, then "yx" must be of ...

**Mathematics**

Try to use remainder therom reverse it from divident subtract remainder then divide with no remainder ans will come

**Combinations Maths**

25 independent, fair coins are tossed in a row. What is the expected number of consecutive HH pairs? If 6 coin tosses in a row give HHTHHH, the number of consecutive HH pairs is 3.

**Combinations Maths**

For how many positive integers n are there exactly ⌊n/2⌋ or ⌈n/2⌉ primes less than or equal to n?

**Geometry**

BC is a triangle with ∠BAC=60∘,AB=5 and AC=25. D is a point on the internal angle bisector of ∠BAC such that BD=DC. What is AD^2? It is not stated that D lies on BC. This assumption is not necessarily true.

**Geometry**

ABC is a right angled triangle with ∠ABC=90∘ and side lengths AB=24 and BC=7. A semicircle is inscribed in ABC, such that the diameter is on AC and it is tangent to AB and BC. If the radius of the semicircle is an improper fraction of the form a/b, where a and b ar...

**Number theroy**

What is the 50th smallest positive integer that can be written as the sum of distinct non-negative integer powers of 3?

**Algebra**

Let S(N) denote the digit sum of the integer N. Let M denote the maximum value of N/S(N), where N is a 3-digit number. How many 3-digit numbers N satisfy N/S(N)=M? The digit sum of an integer is the sum of all its digits. For example, the digit sum of N=1123 is 1+1+2+3=7.

**Algebra**

We define n♡ recursively as follows. 1♡=1; n♡=((n−1)♡)⋅n+1 Find the largest n<1000 such that the last two digits of n♡ are zeroes. Just to make it clear: unlike "n-factorial," "n-heart" is NOT an official mathema...

**Algebra**

How many positive integers n≤1000 cannot be written in the form a2−b2−c2 where a,b and c are non-negative integers subject to a≥b+c?

**Slope Maths**

What is the slope of the line tangent to the quadratic f(x)=4x^2−3x+6 at x=7?

**Limit Math**

Evaluate lim x→∞ 2x/(√(x^2+3)-4) in words 2x divide by(root(xsq +3) -4)

**Trignometry**

ABCD is a square where M and N are midpoints of AD and CD, respectively. If sin∠MBN=a/b, where a and b are coprime positive integers, what is the value of a+b?

**Trignometry**

Let m and M be the minimum and maximum values of the domain of f(x)=sin^−1(x2−35), respectively. What is the value of M−m? sin^-1 is sin inverse

**Trignometry**

The angles in triangle ABC satisfy 6sin∠A=3√(3)sin∠B=2√(2)sin∠C. If sin^2∠A=a/b, where a and b are coprime positive integers, what is the value of a+b?

**Algebra**

The function f(x)=x^4−10x^3+40x^2−80x+64 has four complex roots, one of which is 2−2i. What is the sum of all real and imaginary coefficients of these roots? i here is imaginary unit i.e. i^2 = -1

**Algebra**

A is a 2 by 2 matrix. Given that A=(5 1) (1 5) , what is the value of det(A)? det(A) is determinant of A

**Physics**

A 80 kg climber is standing horizontally on a perfectly vertical cliff face. The climber is 1.8 m tall and is attached by a 2 m long rope fastened around their middle to a point on the cliff above them. What is the normal force the cliff face exerts on the climber in Newtons? ...

**Physics**

i could not get there hw to put angle

**physics**

0.0928 kg

**geometry**

150

**algebra**

Let x = side of square to cut off from each corner 20 - 2x = width of bottom rectangle 28 - 2x = length of bottom rectangle V = x(20 - 2x)(28 - 2x) = 4x(10 - x)(14 -x) = V = 4x(140 - 24x + x²) V = 4(140x - 24x² + x³) Differentiating and equating to zero dV/dx = ...

**algebra**

Let x = side of square to cut off from each corner 20 - 2x = width of bottom rectangle 28 - 2x = length of bottom rectangle V = x(20 - 2x)(28 - 2x) = 4x(10 - x)(14 -x) = V = 4x(140 - 24x + x²) V = 4(140x - 24x² + x³) Differentiating and equating to zero dV/dx = ...

**Calculus**

Oops, sorry about that, the correct answer is 7 (4 * 6) + (5 * -2) + (-1 * 7) 24 + (-10) + (-7) 14 + (-7) 7 7.

**Calculus**

The Dot Product is a scalar (number) (4 * 5) + (5 * -2) + (-1 * 7) 20 + -10 + -7 10 + -7 3 3.

**Psychology**

According to Freud, defense mechanisms are protective methods, by the ego, that reduce anxiety by unconsciously distorting reality. Definitions & Examples: Repression - banishing anxiety-arousing thoughts, feelings, and memories from consciousness. e.g. blocking out your traum...

**Math**

There are 16 oz in 1 lb. So, 1 lb 4 oz = (1 * 16) + 4 = 20 oz -- Each day, Robert feeds his dog 20 oz If the bag is 40 lbs, and 1 lb = 16 oz -- The bag is 640 oz 640 oz of food, divided by 20 oz servings -- It will last 32 days.

**choice**

Healthy behaviors and choices are decisions made when one is conscience of their overall health status, and thus will lead to minimized negative consequences. Overtime, this will positively affect an individual's health status. Conversely, behaviors that are unhealthy igno...

**choice**

Healthy behaviors and choices are decisions made when one is conscience of their overall health status, and thus will lead to minimized negative consequences. Overtime, this will positively affect an individual's health status. Conversely, behaviors that are unhealthy igno...

**math**

2 & 3 are both factors of 6. Meaning whenever 6 goes in a set, it can be replaced by two 3's or three 2's. 6 * 4 6 * 3; 3 * 2 6 * 3; 2 * 3 6 * 2; 3 * 4 6 * 2; 2 * 6 6 * 2; 3 * 2; 2 * 3 6 * 1; 3 * 6 6 * 1; 2 * 9 6 * 1; 3 * 4; 2 * 3 6 * 1; 3 * 2; 2 * 6 6 * 0; 3 * 8 6 * 0...

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