mathland wrote:Mathegocart wrote:Same deal as part (b). The distance from the center of the tube to the wall is R. Plug that in for r(i.e, r=R).

Are you saying that dV/dr = -2kR for part (c)?

Yes.

Easier than I thought. Are you a math teacher?

]]>Mathegocart wrote:mathland wrote:Going back to the picture, can you provide the steps?

Sure. To upload a personal image of yours onto this forum,

1. Upload the image to an image hoster such as postimage. Others have suggested imgur in the past, but it has now been infested with commercialism and other such idiocies of the Internet. Hence why I recommend postimage.2. On the page after you upload your image, you will be presented with a myriad of links. Copy and paste the

Direct Linkinto an tag, i.e [img]DIRECT LINK GOES HERE[/img].I have to join postimage first, right?

You may if you wish, but it's not necessary for uploading images.

]]>#1631. What does the medical term 'Chordoma' mean?

]]>**Categories**

Extrasensory perception (ESP), perception that occurs independently of the known sensory processes. Usually included in this category of phenomena are telepathy, or thought transference between persons; clairvoyance, or supernormal awareness of objects or events not necessarily known to others; and precognition, or knowledge of the future. Scientific investigation of these and similar phenomena dates from the late 19th century, with most supporting evidence coming from experiments involving card guessing. Subjects attempt to guess correctly the symbols of cards hidden from their view under controlled conditions; a better-than-chance percentage of correct calls on a statistically significant number of trials is considered to be evidence of ESP. Although many scientists continue to doubt the existence of ESP, people who claim this ability are sometimes used by investigative teams searching for missing persons or things.

**Telepathy**

Telepathy, direct transference of thought from one person (sender or agent) to another (receiver or percipient) without using the usual sensory channels of communication, hence a form of extrasensory perception (ESP). While the existence of telepathy has not yet been proved, some parapsychological research studies have produced favourable results using such techniques as card guessing with a special deck of five sets of five cards. The agent may simply think of a random order of the five card symbols while the percipient tries to think of the order on which the agent is concentrating. In a general ESP test the sender concentrates on the face of one card at a time while the receiver tries to think of the symbol. Both subjects are, of course, separated by a screen or some greater obstacle or distance. Scores significantly above chance are extremely rare, particularly as testing methods have become more rigorous.

**Clairvoyance**

Clairvoyance, (French: “clear seeing”) knowledge of information not necessarily known to any other person, not obtained by ordinary channels of perceiving or reasoning—thus a form of extrasensory perception (ESP). Spiritualists also use the term to mean seeing or hearing (clairaudience) the spirits of the dead that are said to surround the living. Research in parapsychology—such as testing a subject’s ability to predict the order of cards in a shuffled deck—has yet to provide conclusive support for the existence of clairvoyance.

**Precognition**

Precognition, supernormal knowledge of future events, with emphasis not upon mentally causing events to occur but upon predicting those the occurrence of which the subject claims has already been determined. Like telepathy and clairvoyance, precognition is said to operate without recourse to the normal senses and thus to be a form of extrasensory perception (ESP).

There is a long tradition of anecdotal evidence for foreseeing the future in dreams and by various devices such as observing the flight of birds or examining the entrails of sacrificial animals. Precognition has been tested with subjects required to predict the future order of cards in a deck about to be shuffled or to foretell results of dice throws, but the statistical support for it has generally been less convincing than that from experiments in telepathy and clairvoyance.

**Psychokinesis**

Psychokinesis, also called telekinesis, in parapsychology, the action of mind on matter, in which objects are supposedly caused to move or change as a result of mental concentration upon them. The physical nature of psychokinetic effects contrasts with the cognitive quality of extrasensory perception (ESP), the other major grouping of parapsychological phenomena. Claimed effects of psychokinesis include levitation and metal bending; such displays are common, though fraudulent, in theatrical magic.

Despite experimental investigation, scientific evidence supporting the existence of psychokinesis is lacking. In an example of a psychokinetic test, the subject attempts by thinking or willing to influence thrown dice, causing a certain die face to turn up or causing the die to land in a certain area. Other experiments have focused on the ability of subjects to influence outcomes of random number generators. Some researchers have interpreted the results of such experiments as revealing the existence of very small effects in which consciousness influences outcomes in such random physical systems. Other studies, however, indicate that such conclusions are the result of various forms of bias, including publication bias and confirmation bias. Hence, experimental results, as with other parapsychological phenomena, have been inconclusive.

**Parapsychology**

Parapsychology, Discipline concerned with investigating events that cannot be accounted for by natural law and knowledge that cannot have been obtained through the usual sensory abilities. Parapsychology studies the cognitive phenomena often called extrasensory perception, in which a person acquires knowledge of other people’s thoughts or of future events through channels apparently beyond the five senses. It also examines physical phenomena such as the levitation of objects and the bending of metal through psychokinesis. Though belief in such phenomena may be traced to earliest times, parapsychology as a subject of serious research originated in the late 19th century, partly in reaction to the growth of the spiritualist movement. The Society of Psychical Research was established in London in 1882, and similar societies were later founded in the U.S. and in many European countries. In the 20th century research into parapsychology was also conducted at some universities, notably at Duke University under J. B. Rhine.

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Andrew F. Kay (January 22, 1919 – August 28, 2014) was a businessman and innovator. He was President and CEO of Kaypro, a personal computer company, which at one time was the world's fourth largest manufacturer of computers, and the largest in the world in sales of portable computers.

Kay, a 1940 graduate of MIT, started his career with Bendix followed by two years at Jet Propulsion Laboratory. In 1952, Kay founded Non-Linear Systems, a manufacturer of digital instrumentation. NLS developed a reputation for providing rugged durability in critical applications for everything from submarines to spacecraft. At NLS he invented the digital voltmeter, in 1954.

Kaypro began selling computers in the early 1980s. In 1985, it had more than $120 million in revenues, dwarfing what had been its parent, NLS. But the company's success was relatively short-lived; in 1990 it filed for Chapter 11 bankruptcy protection, and it was liquidated in 1992.

In the late 1990s, Kay founded Kay Computers, which similarly manufactured and sold personal computers. The company lasted for less than ten years.

Kay later was a Senior Business Advisor to Accelerated Composites, LLC.

He co-founded the Rotary Club of Del Mar, California.

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#3903. What does the adjective *firm* mean?

#3904. What does the noun *firmware (Computers)* mean?

#5002.

]]>mathland wrote:Bob wrote:Find dW/dt and then put in the given t value.

B

Hello Bob.

Let me see.

dW/dt = d/dt [35,000 − 20t^2]

dW/dt = -40t

What do I do with dW/dt?

Plug t=2 hours into dW/dt as the problem tells you to.

Ok. Very easy to do when someone explains what is going on.

]]>mathland wrote:Bob wrote:work out dy/dx for the gradient of the tangent line and hence find the equation using y = mx + c.

This line will cross the curve again so work with a pair of simultaneous equations (tangent equation) and (curve equation).

The resulting equation in x will look complicated but you have one extra clue ... you know (1/2 , 1/8) lies on both so the expression must factorise with (x-1/2) or (2x-1) as a factor. That leaves a quadratic implies two more solutions. Wait a mo though. If the line makes a tangent at that point then (2x-1) will be a double factor leaving only a linear equation left for the solution you want.

B.

This is one is a bit unclear.

I hope this explanation of mine may help in clarifying Bob's explanation to you.

To find that specific point Q, we need to find the equation of the tangent line T(y = mx + b) at the point(1/2, 1/8).

So, let's find the derivative of the function y = x^3 so we can find the slope of said line.

y' = 3x^2(per the power rule.)

Plug in x = 1/2 and we get y' = 3(1/2)^2 = 3/4. So the slope, or "m," in the tangent line is 3/4.Now we have y = (3/4)x + b. Plug in the point that the tangent line contains so you can find b, and with that equation, of the tangent line you want to find where it intersects with y = x^3 so you can determine point Q.

Set the ys equal and you will receive

The Tangent Line Equation = x^3.As Bob mentions, you will receive a cubic equation that can be reduced down to a quadratic equation via dividing the cubic by (2x-1)(as you already know that x = 1/2 is a solution to the problem above.)

You will find the other solution to the quadratic, and then determining the slope of the tangent line at Q to y=x^3 at x = other solution is relatively easy.

I will play with one some more.

]]>mathland wrote:Bob wrote:Here again dV/dr is your starting point.

B.

This will take some time to do. Bob, the questions posted are the questions for which the author does not provide a sample for.

(a). Take the derivative of V(R) with respect to R. I.e use the power rule or the limit definition of the derivative.

(b). Plug in R = 0.03 and R = 0.04 into the derivative of V(R).

(c). Determine V'(0.04) - V'(0.03) to find the increase (or decrease) of the rate at which blood is flowing.

Thank you. I will do as you said.

]]>mathland wrote:Mathegocart wrote:You're rather close here, but note that the question states that a tax of 8% is applied(i.e, added onto) the room rate. Your equation as currently written would apply a 92% tax on the hotel rate.

So it should be T(x) = 1.08(99.95x) + 5.00.Where did 1.08 come from?

1.08 simply means that the rate was increased by a tax of 8%. 1.00 increased by 8% is 1.08.

Very cool. Very easy. Questions posted are the questions for which the author does not provide a sample for. The rest of the textbook questions I can easily solve.

]]>dy/dx will tell you the gradient of the tangent line. But you don't know the release point so call it (a,b) The tangent line goes through (a,b) and you can also write the gradient in terms of a and b. So form the equation of the tangent line (y=mx+c)

You can substitute for b using the original equation. You also want the line to go through (1,0) so you cab use this to get an equation for finding a.

B

I gotta play with this some more.

]]>mathland wrote:Mathegocart wrote:Hello mathland,

yup, that's all correct - meet or exceed is indeed >=.How about that? It was a guess, really. It's important to understand the WHY in math.

I agree. There wasn't much more - you just stated the problem in mathematical form. I.e, 299mg * cups of milk + 261mg * cups of juice (meets or exceeds, i.e greater than or equal to) 1000 mg.

Great stuff.

Thanks. Always look for my questions. I absolutely never get enough mathematics.

]]>#7851. What does the term 'Glyptology' mean?

#7852. What does the term 'Gnomonics' mean?

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