# Write as sum difference or multiple of logarithms in real life

This is a manuscript of the 3rd edition, a work in progress sponsored by the US National Science Foundation. The first edition was published by Third Millenium Books, Novato, California, in and as noted below, copyright was reassigned to the author upon breakup of that company. As to conditions for use, Dr. Grosch says "make sure it's as generous as possible.

## How to Write a sum/difference of logarithms as a logarithm « Math :: WonderHowTo

Bring fact-checked results to the top of your browser search. In fact, calculation underlies many activities that are not normally thought of as mathematical.

Walking across a room, for instance, requires many complex, albeit subconscious, calculations. Computers, too, have proved capable of solving a vast array of problems, from balancing a checkbook to even—in the form of guidance systems for robots—walking across a room.

Before the true power of computing could be realized, therefore, the naive view of calculation had to be overcome. The inventors who laboured to bring the computer into the world had to learn that the thing they were inventing was not just a number cruncher, not merely a calculator.

For example, they had to learn that it was not necessary to invent a new computer for every new calculation and that a computer could be designed to solve numerous problems, even problems not yet imagined when the computer was built.

They also had to learn how to tell such a general problem-solving computer what problem to solve.

## Computer - History of computing | rutadeltambor.com

In other words, they had to invent programming. They had to solve all the heady problems of developing such a device, of implementing the design, of actually building the thing. The history of the solving of these problems is the history of the computer.

That history is covered in this section, and links are provided to entries on many of the individuals and companies mentioned. In addition, see the articles computer science and supercomputer. Early history The abacus The earliest known calculating device is probably the abacus.

It dates back at least to bce and is still in use today, particularly in Asia. Now, as then, it typically consists of a rectangular frame with thin parallel rods strung with beads. Long before any systematic positional notation was adopted for the writing of numbers, the abacus assigned different units, or weights, to each rod.

This scheme allowed a wide range of numbers to be represented by just a few beads and, together with the invention of zero in India, may have inspired the invention of the Hindu-Arabic number system. In any case, abacus beads can be readily manipulated to perform the common arithmetical operations—addition, subtraction, multiplication, and division—that are useful for commercial transactions and in bookkeeping.

The abacus is a digital device; that is, it represents values discretely. A bead is either in one predefined position or another, representing unambiguously, say, one or zero.

As any person can attest, adding two digit numbers is much simpler than multiplying them together, and the transformation of a multiplication problem into an addition problem is exactly what logarithms enable. This simplification is possible because of the following logarithmic property: Bytables with 14 significant digits were available for the logarithms of numbers from 1 to 20, and scientists quickly adopted the new labour-saving tool for tedious astronomical calculations.

Most significant for the development of computing, the transformation of multiplication into addition greatly simplified the possibility of mechanization.

In Edmund Gunterthe English mathematician who coined the terms cosine and cotangent, built a device for performing navigational calculations: That first slide rule was circular, but Oughtred also built the first rectangular one in The analog devices of Gunter and Oughtred had various advantages and disadvantages compared with digital devices such as the abacus.

What is important is that the consequences of these design decisions were being tested in the real world. He described it in a letter to his friend the astronomer Johannes Keplerand in he wrote again to explain that a machine he had commissioned to be built for Kepler was, apparently along with the prototypedestroyed in a fire.

He called it a Calculating Clockwhich modern engineers have been able to reproduce from details in his letters.

The device could add and subtract six-digit numbers with a bell for seven-digit overflows through six interlocking gears, each of which turned one-tenth of a rotation for each full rotation of the gear to its right.

A century earlier, Leonardo da Vinci sketched plans for a calculator that were sufficiently complete and correct for modern engineers to build a calculator on their basis.Apr 11,  · Directions: Write each expression as a sum or difference of logarithms.

Then simplify, if possible.

## BetterExplained Books for Kindle and Print

Now here's the problem: log^2*15m The 2 is an exponent in the bottom part of the "log" and the * means "times" or "multiply."Status: Resolved. PREFACE to Web edition.

Computer: Bit Slices from a Life was converted to HTML for the Web by Frank da Cruz in May for the Columbia University Computing History Project with permission and collaboration of Dr.

Grosch. This is a manuscript of the 3rd edition, a work in progress sponsored by the US National Science rutadeltambor.com first edition was published by Third Millenium Books, Novato.

A positive attitude is an important aspect of the affective domain and has a profound effect on learning. Environments that create a sense of belonging, support risk taking and provide opportunities for success help students to develop and maintain positive attitudes and self-confidence.

We can see from this graph that when the neuron's output is close to $1$, the curve gets very flat, and so $\sigma'(z)$ gets very small.

Equations (55) and (56) then tell us that $\partial C / \partial w$ and $\partial C / \partial b$ get very small.

## Early history

This is the origin of the learning slowdown. Question Rewrite as a sum and/or difference of multiples of logarithms: ln((3x^2)/square root 2x+1)).my answer was 2ln(3x) + 1/2ln(2x+1) is this correct? Found 2 solutions by . First Law of Thermodynamics Adding heat Q to a crystal increases its internal energy U: dU dQ (indicates 'proportional') but if the crystal is allowed to expand, some of the added energy will be consumed by expansion dV, so the total energy of the crystal is reduced: dU = dQ - PdV This is effectively the First Law of Thermo: that total energy (heat + P-V work) is conserved.

Chapter Subchapter C