# Posts by Jake

Total # Posts: 2,221

**Algebra**

Use the substitution method to solve -x + 3y=24 5x +8y=-5

*March 23, 2012*

**Calculus and vectors**

|C|=5 and |D|=8. The angle formed by vectors C and D is 35 degrees, and the angle formed by vectors A and C is 40 degrees. Determine |B|. Could someone explain this question

*March 23, 2012*

**fractions**

6/8 pizza left, which can be reduced to 3/4.

*March 23, 2012*

**Calculus and vectors-Help~David**

Thank you very much!

*March 22, 2012*

**Calculus and vectors-Help~David**

Rectangular prism is defined by vectors (2,0,0)(0,9,5) and (0,0,3). Find the volume. I have done this so far, would anyone please verify this. (2,0,0)(0,9,6) (0-2, 9-0, 6-0) =(-2,9,6) (-2,9,6)(0,0,3) =(2,-9,-3) (2)(-9)(-3)=54 cm^3 Therefore volume is 54 cm^3

*March 22, 2012*

**Calculus**

Is B=(2,-1,-6)?

*March 22, 2012*

**Calculus**

If A=(1,2,4) and Vector A+B =(3,1,-2). What is B?

*March 22, 2012*

**Calculus and vectors @ Bob Purs**

I multipled by 2 since its a rectangle, there is an example of similiar to this question but its a triangle.

*March 22, 2012*

**Calculus and vectors @ Bob Purs**

Rectangle side is represented by (2,3) and (-6,4). Find the perimeter of rectangle. Is this correct? (-6-2), 4-3) sqrt(8^2+1^2) sqrt(65) =8.062257748(2) =16.124?

*March 22, 2012*

**Math**

Is this correct? ((-6-2), 4-3) sqrt(8^2+1^2) sqrt(65) =8.062257748(2) =16.124?

*March 22, 2012*

**Math**

Rectangle side is represented by (2,3) and (-6,4). Find the perimeter of rectangle. Do I have to find the magnitude of (2,3) and (-6,4) and square root the answer?

*March 22, 2012*

**Calculus**

Thank you for answering. Don't I have to find the magnitude then use square root of the answer and multiply by 2? If so, could you show it.

*March 22, 2012*

**Calculus**

Rectangle side is represented by (2,3) and (-6,4). Find the perimeter of rectangle. Could someone please help~

*March 22, 2012*

**Calculus and vectors**

Could someone explain to me how I can find the area/perimeter/volume of a rectangular prism if I am given R^3 points. For example find area of rectangular prism given pts (2,3,4)(5,3,2), similar to this.

*March 21, 2012*

**math**

1.5

*March 20, 2012*

**Calculus and vectors**

Bob can swim at a rate of 5km/h. He is in a river that is flowing at a rate of 9 km/h. a) if bob swims upstream, what is his relative velocity to the ground? b)if bob swims downstream, what is his relative velocity to the ground? c) Someone decides to help Bob out of the water...

*March 20, 2012*

**physics**

Bob can swim at a rate of 5km/h. He is in a river that is flowing at a rate of 9 km/h. a) if bob swims upstream, what is his relative velocity to the ground? b)if bob swims downstream, what is his relative velocity to the ground? c) Someone decides to help Bob out of the water...

*March 19, 2012*

**Math**

Bob can swim at a rate of 5km/h. He is in a river that is flowing at a rate of 9 km/h. a) if bob swims upstream, what is his relative velocity to the ground? b)if bob swims downstream, what is his relative velocity to the ground? c) Someone decides to help Bob out of the water...

*March 19, 2012*

**Chemistry**

Why doesn't water undergo electrolysis? Why does Na2SO4 undergo electrolysis?

*March 19, 2012*

**trig**

verify that 2/1+cos theta - tan squared (theta/2) = 1

*March 19, 2012*

**Math**

Multiplying a vector by a scalar results in: a) a scalar b) a perpendicular vector c) a collinear vector c) a parallel scalar

*March 18, 2012*

**Math**

Sabrina and John cut a pie into 4 slices. Sabrina eats 2 slices. John eats the rest. What fraction names the part of the pie that John eats?

*March 14, 2012*

**Biology**

Among humans, increased interest in food intake normally occurs _____. only after the production of glucose in the liver can no longer meet metabolic needs when fewer calories are taken in than are expended, but only after the body depletes its reserves of fat in the liver via...

*March 14, 2012*

**SCIENCE/ earth**

Thanks Ms Sue!!!

*March 14, 2012*

**SCIENCE/ earth**

plate tectonics crossword puzzle what Qs and As can i use??????? PLZZZZZ HELP ME!!!!!!!!!!!!!

*March 14, 2012*

**PHYSICS**

A space explorer is 4.6 billion km away from a certain star, and observes that the gravitational force of attraction exerted on the spacecraft by the star is 500 N. What will the force become when the craft has approached to a position 2 billion km from the star?

*March 11, 2012*

**PHYSICS**

Determine the value for the acceleration due to gravity at the surface of the planet Mars, given the following data: Mass of Mars = 6 .42 x 10^23 kg Radius of Mars = 3.37 x 10^6 m Thanks!

*March 10, 2012*

**chemistri**

so are dispersion forces one of them?

*March 10, 2012*

**chemistri**

what are van der waals forces

*March 10, 2012*

**work hours**

If i am making $11.50 an hour, 4 hours a day from monday through friday, how much do i get by the end of the month?

*March 8, 2012*

**Calculus**

I keep getting the wrong answer :| I don't know what I have done wrong...

*March 7, 2012*

**Calculus**

Could someone help me setup an equation for this equation? --------------------------------- A city bus system carries 4000 passengers a day throughout a large city. The cost to ride the bus is $1.50/person. The owner realizes that 100 fewer people would ride the bus for each...

*March 7, 2012*

**physical science**

6. If one body is positively charged and another body is negatively charged, free electrons tend to [A. move from the negatively charged body to the positively charged body.] B. remain in the positively charged body. C. remain in the negatively charged body. D. move from the ...

*March 6, 2012*

**INTRODUCTION TO THE SHORT STORY, PART 1**

d is correct answer just took the pf test

*March 5, 2012*

**Engish**

I need to find the statment of life in the call of the wild by jack london

*March 4, 2012*

**Calculus**

The fuel efficiency, E, in litres per 100 km, for a car driven at speed v, in km/h is E(v)=1600v/(v^2+6400). a) Determine the legal speed speed that will maximize the fuel efficiency if the speed limit is 50 km/h. The answer is 50 km/h but my teacher said it can't be that...

*March 4, 2012*

**Calculus**

An object moves in a straight line. Its velocity, in m/s, at time t is v(t)=4t^2/(1+t^2),t≥0. Determine the maximum and minimum velocities on the interval 1≤x≤4.

*March 3, 2012*

**Math**

The concentration C(t), in milligrams per cubic centimetre, of a certain medicine in a patient's bloodstream is given by C(t)= (0.1t)/(t+3)^2 where t is number of hours after the medicine is taken. Determine the maximum and minimum concentrations between the first and ...

*March 3, 2012*

**Calculus**

An object moves in a straight line. Its velocity, in m/s, at time t is v(t)=4t^2/(1+t^2),t≥0. Determine the maximum and minimum velocities on the interval 1≤x≤4. The answer says min. velocity is 0m/s but has no maximum?

*March 3, 2012*

**Calculus**

Can someone explain this question to me? What intervals should I use to test whether or not the graph is concave up or down. I know that no points or equations are given so we have to estimate. Here is the URL for the graph. imgur dotcom/FdQCV

*March 3, 2012*

**Calculus**

Let f(x)=(2x^3-x^2+2x+1)/(x^2+1). What is the equation of the oblique asymptote of f(x)? Can someone show me how to do the long division one for this question. I have always used synthetic division but realized there are some questions that require to do long division.

*February 29, 2012*

**Calculus**

Let f(x)=x^2-8x+16 and g(x) x^2-16. For what values of x is f(x)/g(x) increasing? Explain plz~

*February 28, 2012*

**Physics 161**

what is your "m" in your equations stand for?

*February 28, 2012*

**Physics 161**

A cat dozes on a stationary merry-go-round, at a radius of 6.9 m from the center of the ride. The operator turns on the ride and brings it up to its proper turning rate of one complete rotation every 7.3 s. What is the least coefficient of static friction between the cat and ...

*February 28, 2012*

**Calculus**

Let f(x)= (3x^2-2x+1)/(x-1). What are the types of asymptotes of f(x)? What are the equations of all the asymptotes of f(x)? The types of asymptote are vertical and oblique? x=1? Is there something wrong I did

*February 28, 2012*

**Calculus**

Determine the points at which f'(x)=0 for each of the following functions: f(x)= x^3+6x^2+1 f'(x)=3x^2+12x What to do next?

*February 25, 2012*

**Calculus**

The fuel efficiency, E, in litres per 100 km, for a car driven at speed v, in km/h is E(v)=1600v/(v^2+6400) a) determine the legal speed that will maximize the fuel efficiency using speed limit of 50 km/h

*February 24, 2012*

**Calculus**

An object moves in a straight line. Its velocity, in m/s, at time t is v(t)=4t^2/(4+t^3), t>(greater or equal)0. Determine the maximum and minimum velocities over time interval 1<t<4 I got minimum as 1= 4/5. However for maximum at t=4, I got 16/17 but the book says 4/3?

*February 22, 2012*

**Calculus**

An object moves in a straight line. Its velocity, in m/s, at time t is v(t)=4t^2/(4+t^3), t>(greater or equal)0. Determine the maximum and minimum velocities over time interval 1<t<4 I got minimum as 1= 4/5. However for maximum at t=4, I got 16/17 but the book says 4/3?

*February 22, 2012*

**Calculus**

For which point(s) on the graph of f(x)=5x/(x+2) is the slope of the tangent 2/5? a) (-3,15) b) (7, 35/9) c) (3,3) and (-7,7) d) (24, 60/13) Answer is C?

*February 21, 2012*

**Calculus**

Thanks!

*February 21, 2012*

**Calculus**

Verify if correct or not please =) What is the slope of the normal to y= (x^2-1)/(x+5) at (1,0) a) -3 b) -1/2 c) -1/3 d) 1/3 Answer is A, -3. ---------------------------------------- What is the y-intercept of the line that is tangent to f(x)=4/(3x+1) at (-1, -2)? a)-5 b) -3/4...

*February 21, 2012*

**Math**

if h(t) = 17.4 * 1.23^1, find h(13)

*February 20, 2012*

**math - probability**

1. 7 over 8

*February 20, 2012*

**Ground School: Regulations**

I am working on my private pilot license and these regulation things, HOW do you learn all of them?????????

*February 20, 2012*

**Piloting: stumped**

We are taking the class together and have questions about it. we aren't the same person!!

*February 20, 2012*

**math**

If you flip 2 coins then 25% chance

*February 20, 2012*

**math**

4 out of 5 that the number will be less than 900

*February 20, 2012*

**Math**

if f is an exponential function, and f(5)=20 and f(9) = 14, use the add-multiply property to calculate f(13),f(17), and f(21). Show your method

*February 19, 2012*

**chemistryyyy**

A solution is made by dissolving 0.0100 mol of HF in enough water to make 1.00 L of solution. At 23 °C, the osmotic pressure of the solution is 0.308 atm. What is the percent ionization of this acid? Please help.

*February 19, 2012*

**Calculus-derivatives**

Verify these answers~ 1. For what value(s) of x does f(x)=(x^2-16)^5 have a horizontal tangent? a) x=-4,4 b) x=-4,0,4 c) x=0 d) x=0,4 Answer is B, x=-4,0,4 --------------------------------------- 2. What is the derivative of f(x)=(3x^2+7)^3? a) f'(x)=3(3x^2+7)^2 b) f'(...

*February 18, 2012*

**Calculus-derivatives**

What is the slope of the tangent of each curve at given point y=√(16x^3), (4,32) If I find the derivative of y=√(16x^3) Will it be 16/-x^3

*February 15, 2012*

**Calculus-derivatives**

So for number 1 the answer is t=1 -2+2t=0 2t=2 2/2=1

*February 15, 2012*

**Calculus-derivatives**

Oh crap nvm!

*February 15, 2012*

**Calculus-derivatives**

For number one we find the derivative of 3-2t+t^2 wouldn't that be t-2?

*February 15, 2012*

**Calculus-derivatives**

Explain how to do these questions~ 1. An object moves in a straight line with its position at time t seconds given by s(t) = 3-2t+t^2, where s is the measured in metres. At what time is the object not moving? 2. Determine the coordinates of the point(s) on the graph of y=3x- 1...

*February 15, 2012*

**Math**

a ship leaves sydney heads and travels 45 km due east. it then returns and travels 86 km due north. how far is it from its starting point? please guys step by step.. thank you in advance.

*February 15, 2012*

**Calculus**

Explain how you got the answer please.

*February 14, 2012*

**Calculus**

What is the derivative of 6/x?

*February 14, 2012*

**Calculus**

For each function, find the derivtive f'(a) for given value of a f(x) = sqrt(x+1), a=0

*February 14, 2012*

**Calculus**

Thank you~

*February 13, 2012*

**Calculus**

May I know where you got 5a + 5h - 2

*February 13, 2012*

**Calculus**

Find each function, find f(a+h) and f(a+h)-f(a) a) f(x)=5x-2

*February 13, 2012*

**English**

What are 25 facts about Mr. Frank after the annex

*February 13, 2012*

**Calculus**

Why is it important to determine continuity of the function?

*February 13, 2012*

**Math**

State the equation of the line passing through the points (7,-1) and (2,2) a) 5x+3y-16=0 b) -5x-3x-16=0 c) -3x - 5y - 16=0 d) 3x + 5y-16=0 ------------------------------------ Is letter D correct?

*February 12, 2012*

**Chemistry**

How do you find the ratio of moles of oxygen to moles of tin? What would be the Empirical formula of tin oxide from the result of ratio? From my calculations I got the moles as: Moles of oxygen = 1.761 x 10^-2 Moles of Tin = 8.944 x 10^-3 Thanks!

*February 11, 2012*

**Calculus**

Examine the continuity of the function h(x)=[-x, if x<0 .......0, if x=0 .......x, if x>0 I don't understand this question...

*February 10, 2012*

**Calculus**

Thank you~~

*February 8, 2012*

**Calculus**

Determine the equation of the line described by the given information. a) slope -2/3, passing through (0,6) b) passing through points (2,7) and (6,11) c) parallel to y=4x-6 passing through point (2,6)

*February 8, 2012*

**Calculus**

Determine an expression, in simplified form, for the slope of the secant PQ. Given: P(1,3) , Q(1+h, f(1+h)) , where f(x) = 3x^2 PQ=Y2-Y1/X2-X1 I keep getting wrong answer, arghhh.

*February 8, 2012*

**Calculus**

How to rationalize this question? (√3 - √2)/(√3+√2) Do I multiply those two by(√3 - √2) or (√3 + √2)

*February 7, 2012*

**algebra**

How do you write someone is older than 27 by less than 38 as an inequality?

*February 4, 2012*

**Physics**

An elevator (mass 4175 kg) is to be designed so that the maximum acceleration is 0.0700g. What is the maximum force the motor should exert on the supporting cable?

*February 1, 2012*

**Precalculus**

How can i write this in log form 5^-2 = 0.04

*February 1, 2012*

**Precalculus**

Quad III and IV? May I know how you got 3.86132? and value for quad IV?

*January 31, 2012*

**Precalculus**

Solve for x, 0<x<2pi 3sin^2x - sinx -2=0 Its not factorable, do I use quadratic formula?

*January 31, 2012*

**Precalculus**

The answer says:16.0 or 74.0 degrees :|

*January 31, 2012*

**Precalculus**

When a projectile leaves a starting point at an angle of elevation of theta with a velocity v, the horizontal distance it travels is determined by: d=v^2/(32) sin2theta Where d is measured in feet and v in feet per second. An outfielder throws the ball at a speed of 75 miles ...

*January 31, 2012*

**Physics**

10m/s

*January 31, 2012*

**Precalculus**

Write 4log2+log6-log3 as a single logarithm. Explain with steps please!~~

*January 30, 2012*

**Precalculus**

If the base was 2 then it would be cuberoot 2^6?

*January 29, 2012*

**Precalculus**

Evaluate log(Base4) ^3sqrt64 (The ^3 is an exponent infront of sqrt 64) I keep getting wrong answer :|

*January 29, 2012*

**Precalculus**

Solve for x: 6^(x+3) - 6^x = 215. I got answer as 1, is it correct?

*January 29, 2012*

**Precalculus**

Thankk you! Took me long to figure it out!

*January 28, 2012*

**Precalculus**

Solve 5^(2-x) = 1/125 for x.

*January 28, 2012*

**Math**

How do I solve this if there is no equation to this 1. The population of the bacteria in a Petri dish increases by a factor of 10 every 10 hour. If there are initally 20 bacteria in the dish, how long will it take before the population increases to 60,000 to the nearest tenth ...

*January 28, 2012*

**history**

What is the term for the power to make final decisions?

*January 28, 2012*