logarithm
(noun)
the exponent by which another fixed value, the base, must be raised to produce that number
Examples of logarithm in the following topics:
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Bases Other than e and their Applications
- These are $b = 10$ (common logarithm); $b = e$ (natural logarithm), and $b = 2$ (binary logarithm).
- In this atom we will focus on common and binary logarithms.
- The major advantage of common logarithms (logarithms in base ten) is that they are easy to use for manual calculations in the decimal number system:
- Binary logarithm ($\log _2 n$) is the logarithm in base $2$.
- For example, the binary logarithm of $1$ is $0$, the binary logarithm of $2$ is 1, the binary logarithm of $4$ is $2$, the binary logarithm of $8$ is $3$, the binary logarithm of $16$ is $4$, and the binary logarithm of $32$ is $5$.
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Derivatives of Logarithmic Functions
- The general form of the derivative of a logarithmic function is $\frac{d}{dx}\log_{b}(x) = \frac{1}{xln(b)}$.
- Here, we will cover derivatives of logarithmic functions.
- First, we will derive the equation for a specific case (the natural log, where the base is $e$), and then we will work to generalize it for any logarithm.
- Next, we will raise both sides to the power of $e$ in an attempt to remove the logarithm from the right hand side:
- We do this by taking the natural logarithm of both sides and re-arranging terms using the following logarithm laws:
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Exponential and Logarithmic Functions
- Both exponential and logarithmic functions are widely used in scientific and engineering applications.
- The logarithm of a number $x$ with respect to base $b$ is the exponent by which $b$ must be raised to yield $x$.
- In other words, the logarithm of $x$ to base $b$ is the solution $y$ to the equation $b^y = x$ .
- The logarithm to base $b=10$ is called the common logarithm and has many applications in science and engineering.
- The binary logarithm uses base $b=2$ and is prominent in computer science.
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Logarithmic Functions
- The logarithm to base $b = 10$ is called the common logarithm and has many applications in science and engineering.
- The binary logarithm uses base $b = 2$ and is prominent in computer science.
- It follows that the logarithm of 8 with respect to base 2 is 3, so log2 8 = 3.
- What would be the logarithm of ten?
- The logarithm is denoted "logb(x)".
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The Natural Logarithmic Function: Differentiation and Integration
- Differentiation and integration of natural logarithms is based on the property $\frac{d}{dx}\ln(x) = \frac{1}{x}$.
- The natural logarithm, generally written as $\ln(x)$, is the logarithm with the base e, where e is an irrational and transcendental constant approximately equal to $2.718281828$.
- The natural logarithm allows simple integration of functions of the form $g(x) = \frac{f '(x)}{f(x)}$: an antiderivative of $g(x)$ is given by $\ln\left(\left|f(x)\right|\right)$.
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Further Transcendental Functions
- Examples of transcendental functions include the exponential function, the logarithm, and the trigonometric functions.
- Note that, for $ƒ_2$ in particular, if we set $c$ equal to $e$, the base of the natural logarithm, then we find that $e^x$ is a transcendental function.
- Similarly, if we set $c$ equal to $e$ in ƒ5, then we find that $\ln(x)$, the natural logarithm, is a transcendental function.
- One could attempt to apply a logarithmic identity to get $\log(10) + \log(m)$, which highlights the problem: applying a non-algebraic operation to a dimension creates meaningless results.
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Integration Using Tables and Computers
- Here are a few examples of integrals in these tables for logarithmic functions:
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Alternating Series
- The first fourteen partial sums of the alternating harmonic series (black line segments) shown converging to the natural logarithm of 2 (red line).
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Separable Equations
- ., combine all possible terms, rewrite any logarithmic terms in exponent form, and express any arbitrary constants in the most simple terms possible).
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The Integral Test and Estimates of Sums
- The harmonic series $\sum_{n=1}^\infty \frac1n$ diverges because, using the natural logarithm (its derivative) and the fundamental theorem of calculus, we get: