Factorials shortcuts | Summary and Q&A

TL;DR

Factorials are used to find the product of every whole number before a given number and are commonly used in combinations, permutations, and algebraic calculations.

Key Insights

• #️⃣ Factorials represent the product of every whole number before a given number.
• 😑 Factorials are useful in calculating combinations, permutations, and algebraic expressions.
• ❓ 0 factorial is defined as 1, which may seem counterintuitive.
• 🍉 Factorials can be simplified by canceling out common terms.
• 🍉 Efficient calculations involving factorials can be done by canceling out common terms to avoid large numbers.
• ❓ Factorials are often used in mathematics to solve problems related to arrangements and orderings.
• 🎮 Understanding factorials is crucial in later videos on combination and permutation calculations.

Transcript

good day welcome to Tech math Channel what we're going to be having a look at in this video is factorials uh what are these guys well these you would have seen before probably written like this um or maybe you've just seen the special button on your calculator so they're things like five factorial here and what they are is pretty much where you're ... Read More

Questions & Answers

Q: What is a factorial?

A factorial is the product of every whole number below a given number. For example, 5 factorial (5!) is equal to 5 * 4 * 3 * 2 * 1, which equals 120.

Q: Why is 0 factorial equal to 1?

Although it may seem counterintuitive, 0 factorial (0!) is defined as 1. This is because it is used in combination and permutation calculations, where its value is necessary for certain equations to work.

Q: How can factorials be used to simplify calculations?

Factorials can be simplified by canceling out common terms. For example, when calculating 5 factorial divided by 3 factorial, you can cancel out the terms 3!, resulting in 5 * 4, which equals 20.

Q: How can factorials be used to solve large calculations efficiently?

To solve calculations involving large factorials, such as 70 factorial over 68 factorial, you can simplify the problem by canceling out common terms. For example, 70 * 69 can be obtained by canceling out 68 factorial.

Summary & Key Takeaways

• Factorials are denoted with an exclamation mark and represent the product of every whole number below a given number.

• They are used to calculate the number of different ways objects can be arranged.

• Factorials are also used in combination and permutation calculations.