Thursday

August 21, 2014

August 21, 2014

Total # Posts: 56

**Physics**

A plane flying in a straight line at constant altitude of 2000 m above the ground with a speed of 200m/s drops an object. Explain how the velocity of the object is actually affected by air resistance. Show how the resistivity force of air and velocity of the object varies with...
*March 3, 2014*

**Math (Variation)**

The cost of a pizza varies directly as the square of its radius. If a pizza with a 6-inch radius costs ₱148.00, how much should a pizza with an 11-inch radius cost?
*February 11, 2014*

**Basic Linear Algebra**

1. At what point does the graph of f(x)=3x-12 crosses the x-axis? 2.At what point does the graph of f(x)=5x+1 crosses the y-axis?
*February 5, 2014*

**Chemistry**

Can you show me the solution and result please?
*October 10, 2013*

**Math (Combinatorics)**

40 students attended the brilliant summer camp at Stanford University. "k" of the students at the camp are working on math problems and the others are working on non-math problems. One of the camp mentors noticed that whenever all the students were partitioned into 2...
*June 26, 2013*

**Math (Trigonometry [Polar Form])**

Let z be a complex number such that z = 2(cos 8∘ + i cos 82∘).Then z^5 can be expressed as r(sin α∘+ i cos α∘), where r is a real number and 0 ≤ α ≤ 90. What is the value of r+α? Hint to solve: Example Question: Let z be ...
*June 22, 2013*

**Math (Trigonometry)**

θ is an acute angle such that tan(θ)=1/4. What is the value of 17√17*(sinθ+cosθ)?
*June 22, 2013*

**Math (Geometric Progression)**

5 distinct positive reals form an arithmetic progression. The 1st, 2nd and 5th term form a geometric progression. If the product of these 5 numbers is 124 4/9, what is the product of the 3 terms of the geometric progression? Note: The phrase "form an arithmetic ...
*June 22, 2013*

**Math**

Three ships — the Nina, the Pinta, and the Santa Maria — are setting sail from Spain on a mission to find the shortest route to the West Indies. The year is 1492 and Columbus is about to sail the ocean blue... "NO! It can't be so!" shouted Captain ...
*June 20, 2013*

**Calculus (Arc Length)**

Consider the helix parametrized with the vector equation r(t)=cos t i+ sin t j + t k. The length L of the helix between the points (1,0,0) and (1,0,6π) is equal to aπ. What is the value of a^2?
*June 20, 2013*

**Geometry**

Triangle ABC has side lengths AB=8, BC=12 and CA=14. Given that D, E and F are midpoints of BC, CA and AB, respectively. Find the value of AD^2+BE^2+CF^2.
*June 5, 2013*

**Geometry**

Triangle ABC has side lengths AB=8, BC=12 and CA=14. Given that D, E and F are midpoints of BC, CA and AB, respectively. Find the value of AD^2+BE^2+CF^2.
*June 4, 2013*

**Math**

Thanks :)
*May 31, 2013*

**Math**

120 or 180? :)
*May 31, 2013*

**Math**

Sixty men working on a construction job have done 1/3 of the work in 18 days. The project is behind schedule and must be accomplished in the next twelve days. How many more workers need to be hired?
*May 31, 2013*

**Trigonometry**

Given that sin(2θ)=2/3, the value of sin^6θ+cos^6θ can be written as a/b with a and b as coprime positive integers. Find a+b.
*May 27, 2013*

**Trigonometry**

There are four complex fourth roots to the number 4−4√3i. These can be expressed in polar form as z1=r1(cosθ1+isinθ1) z2=r2(cosθ2+isinθ2) z3=r3(cosθ3+isinθ3) z4=r4(cosθ4+isinθ4), where ri is a real number and 0∘≤...
*May 27, 2013*

**Math (Absolute Value Inequality)**

Thanks MathMate :)
*May 26, 2013*

**Math (Absolute Value Inequality)**

Thanks, but how do I find the value of x?
*May 26, 2013*

**Math (Absolute Value Inequality)**

Find the maximum value of a such that the following statement is true: If ∣x−8∣<a, then x^2−11x−210<0.
*May 26, 2013*

**Math (Absolute Value Inequality)**

Let a and b be the maximum and minimum value of x, respectively, satisfying the inequality |x+19|+|x−22|≤137, then what is a−b?
*May 23, 2013*

**Math (Absolute Value Inequality)**

Find the maximum value of a such that the following statement is true: If ∣x−8∣<a, then x^2−11x−210<0.
*May 23, 2013*

**Math (Algebra)**

If the ratio of the roots of the quadratic equation x^2−28x+A=0 is 2:5, what is the product of the roots of the quadratic equation x^2+Ax+2A+3=0?
*May 22, 2013*

**Math (Algebra)**

For real numbers a and b, if f(x)=x^2−ax+b satisfies f(5+7i)=2a, what is the product of the two roots of the equation f(x)=0?
*May 22, 2013*

**Probability**

Bret and Shawn are playing a game where each turn the players roll a 20-sided die fair and then add the number they get to their score. The winner is the player with the highest score at the end of the game (there may be a tie). Before the last turn, Shawn is winning by 10 ...
*May 22, 2013*

**Trigonometry**

The quadratic equation x^2−9x+10=0 has roots tanα and tanβ, where 0∘<α+β<180∘. What is the measure of α+β (in degrees)?
*May 21, 2013*

**Trigonometry**

Γ is the circumcircle of triangle ABC with radius 12√2. If 9cos(∠B+∠C)cos∠A=−1, what is the value of BC?
*May 21, 2013*

**Math (Algebra)**

f(x)=x^4+ax^3+bx^2+cx+d and has real coefficients. If two of the roots are 4−i and 2+3i, what is the value of a+b+c+d?
*May 21, 2013*

**Math (Algebra)**

thanks a lot steve
*May 21, 2013*

**Math (Algebra)**

One root of the quadratic equation x^2 − 2x + m = 0 is 9. If the other root is n, what is n−m?
*May 21, 2013*

**Math (Algebra)**

An elevator named L in "63 Building" in Seoul is notorious for its low speed. It takes 3 seconds for L just to move one floor. It takes another 20 seconds for it to have its door open and close automatically. What is even more frustrating, is that the elevator ...
*May 11, 2013*

**Math**

5 distinct positive reals form an arithmetic progression. The 1st, 2nd and 5th term form a geometric progression. If the product of these 5 numbers is 124 4/9, what is the product of the 3 terms of the geometric progression? Note: The phase "form an arithmetic progression...
*May 11, 2013*

**Math (Percentage)**

An upscale clothing boutique charges $300 for a brand name pair of jeans, which is 50% more than the amount it costs the store to buy one pair of these jeans. As a benefit of working there, employees can purchase the pair of jeans at 30% off the store's cost. How much (in...
*May 7, 2013*

**Math (Percentage)**

The price of a hat is reduced by a% from its regular price, and then is raised by a% from the reduced price. If the resulting price is an 81% discount from the regular price, what is a?
*May 7, 2013*

**Math (Algebra)**

For each degree 17 polynomial f with real coefficients, let sf be the number of real roots (counted with multiplicity). Let S be the set of all possible values of sf. What is |S|?
*May 7, 2013*

**Math (Algebra)**

If a is a real number and a cubic equation f(x) = x^3 − 8x^2 + (a+12)x − 2a has a repeated root, what is the sum of all the possible values of a?
*May 7, 2013*

**Math (Algebra)**

If f(x) is a polynomial with real coefficients such that f(7+5i) = 39 + 13i, then f(7−5i) = a + bi. What is the value of a+b?
*May 7, 2013*

**Math (Algebra)**

A and B are real numbers such that the two quadratic equations 13x^2 + 3x +2 = 0 and Ax^2 + Bx + 5 = 0 have a common root. What is the value of A+B?
*May 7, 2013*

**Math (Combinatorics)**

A lottery ball drawing machine has 50 balls, each labeled with a distinct integer from 1 to 50. Every Sunday, four different balls are drawn to determine the winning numbers. You have last Sunday's ticket with the numbers {3,7,12,15}. You missed the drawing, but heard that...
*May 6, 2013*

**Physics**

A roller coaster works by gravitational energy. The coaster car is pulled up to a high point and then released, rolling downwards on the track through all manners of curves and loops. I have a short roller coaster car that I pull up to the top of a hill of height H. The ...
*May 6, 2013*

**physics**

Thank you drwls :)
*June 1, 2012*

**physics**

Got a question that I'm not quite sure how to approach: "A force of 2500 N acting on the area of 120cm3 evokes a pressure of:" This is all the info given in the question.
*June 1, 2012*

**College math**

Highwq curves. If a circular curve without any banking has a radius of R feet, the speed limit L in miles per hour is L = 1.5 aqrt(R) (a) Find the speed limit for a curve having a radius of 400 feet. (b). If the radius of a curve doubles, what happens to the speed limit? (c.) ...
*April 30, 2011*

**College math**

Highway curves If a circular curve without any banking has a radius of R feet, the speed limitL.in miles per hour for the curve is L=1.5 R. (a.)Find the speed limit for a curve having a radius of 400 feet. (b.) If the radius of a curve doubles, what happens to the speed limit...
*April 28, 2011*

**college math**

Braking distance The braking distance y in feetthat it takes for a car to stop on wet ,level pavement can be estimated by y = 1/9 x^2, where the x is the speed of the car in miles per hour Find the speed associated with with each braking distance. (a.) 25 feet (b.) 361 (c.) 784
*April 28, 2011*

**College Math**

Hooke's Law the table shows the distance D that a spring stretches when a weight W is hung on it. W (pounds 2 6 9 15 D (inches) 1.6 4.8 7.2 12 (a.) Do the data represent direct or inverse variation? Explain. (b.) Find an equation that models the data. (c.) How far will the...
*April 28, 2011*

**12th grade Trigonometry **

theta = 209,55192° theta = 76,70829°
*March 4, 2011*

**English Grammar**

indeed, it is 'just because' .... one of the irregularities of the English language, in some countries, 'I am going to home' is actually common
*March 4, 2011*

**English**

always talk English, doesn't matter if it's their first or 32234th class
*February 27, 2011*

**math**

1 foot = 12 inch 1 square foot = 144 square inches not hard now right
*February 11, 2011*

**Algebra**

(x + 3)³ = x³+ 3x²3 + 3x3² + 3³ (x - 3)³ = x³ - 3x²3 + 3x3² - 3³
*February 10, 2011*

**Algebra 2**

multiply everything by (x-4) ==> x+2 + x²(x-4) + 6*(x-4)=0 ==> x³ - 4x² + 7x -22 =0 ==> search for 'cardano method' glhf
*February 10, 2011*

**Algebra**

nice ... line
*February 10, 2011*

**calculus**

just use the vertex method... f(x) = a*(x-b)+h with : a : what we're searching for (initially) f(x) : 1 (from point (-1;1)) x : -1 (from point (-1;1)) b : x coordinate of the vertex : 1 h : y coordinate of the vertex : -13 => 1 = a*(-1-1)² -13 => a = 10/4 fill ...
*February 10, 2011*

**algebra**

try to get x or y singled out in the easiest equation (or just pick) fe for the first one : y = 13/5 fe for the second one : x = (2y+9)/2 then fill in that x or y in the other equation fe for the first one : x+(13/5)/2 +30 = 0 fe for the second one : 2*((2y+9)/2) + 2y = 9 by ...
*February 10, 2011*

**Watershed?**

im in flvs 2 lol
*November 1, 2006*

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