Search the courses, subjects, tracks, games and features, or jump straight to a page.
Learn it your way
A short class with Sarah and her students. The other ways are under More.
Sign up free to listen. Transcripts are free to read.
Today, we’re going to explore what a logarithm is. Remember our exponentials like 2^3 = 8? Well, logarithms let us express that in a different way. Can anyone tell me what the logarithmic form would be?
Is it log_2(8) = 3?
Exactly! This is how we express it. Logarithm answers the question: To what exponent must the base be raised to get a given number? You can think of it as a reverse operation of raising numbers.
So, logarithms simplify things by reversing exponentiation?
Correct! It’s like undoing multiplication and division, but in exponent terms. Let's keep that in mind!
Now that we have an understanding, let’s break it down. We have three main components in a logarithm. Who can name them?
The base, the argument, and the exponent?
Great job! The base is the number we raise, the argument is what we are trying to find the exponent for, and the exponent is what we’re solving for. Let’s look at this with the example log_2(8) = 3 again. What's the base and argument here?
The base is 2, and the argument is 8!
Exactly! And that leads us to the conclusion that exponentiation and logarithms work hand-in-hand.
Can anyone tell me how logarithms are useful in real-world applications?
I read they're used in science and engineering?
That's correct! They help simplify calculations in those fields. Since logarithms deal with exponents, they can also help us analyze exponential growth or decay in populations or finance.
So they are really helpful when handling large numbers or calculations?
Yes! Logarithms reduce the complexity of calculations, especially when dealing with big numbers.
A function that expresses the exponent to which a base must be raised to yield a certain number.
The number that is raised in an exponential equation.
The number that becomes the output of the logarithmic function.
The output of the logarithmic function.
Log from base to number, it’s a swap, not a blunder.
Imagine being a detective, trying to find out how many times a secret ingredient is used to create a strong potion. Logarithm is your tool to uncover the mystery without guessing!
Remember 'BAE': Base, Argument, Exponent — the key players in every logarithmic equation!
L.A.D - Logarithm, Argument, Base — it’s how we keep our equations in place!
Term
Logarithm
Click to flip
Term
Base
Click to flip
Term
Exponent
Click to flip
Term
Argument
Click to flip
A logarithm answers the question of what exponent must the base be raised to obtain a specified number.
The base in a logarithmic expression is the number that is raised to a power.
The argument in a logarithmic expression is the number for which the logarithm is being calculated and must be positive.
An exponent is the power to which a number (the base) is raised.
This section introduces the concept of logarithms as the inverse operation of exponentiation, providing definitions and foundational relationships.
Logarithms simplify calculations related to multiplication, division, and exponents. The section explains the definition of a logarithm in terms of exponentiation and gives examples to illustrate the concept, establishing a vital connection between logarithms and exponents.
Logarithms are mathematical functions that serve as the inverse of exponentiation. The basic definition states that if we have an equation in the form of 𝑎^𝑥 = 𝑏, the logarithmic form of that equation is written as log_b(𝑏) = 𝑥, where:
For example, from the equation 2^3 = 8, we derive that log_2(8) = 3.
This section emphasizes the importance of understanding logarithms as it lays the groundwork for further exploring their properties, rules, and applications in mathematics and real-world problem-solving.