Example: Using soh cah toa | Basic trigonometry | Trigonometry | Khan Academy

TL;DR

Learn how to find the cosine and sine of an angle in a right triangle using the definitions of trigonometric functions.

Transcript

我们来练习一下直角三角函数比， 还有直角三角函数。 我们来求一下角theta（∠θ）的正弦和余弦。 先求余弦。 现在我们知道这是角theta （∠θ） And it is indeed a right triangle. So I'll give you a few seconds to think about that. Well to answer this you just have to remember the definitions of the trig functions. To help us there, we'll use the mnemonic soh cah toa. Soh Cah Toa soh cah toa And the part of soh cah ... Read More

Key Insights

• 🗯️ The definitions of trigonometric functions (soh cah toa) are important in solving problems involving right triangles.
• 👨‍💼 Cosine represents adjacent over hypotenuse, while sine represents opposite over hypotenuse.
• 🗯️ The Pythagorean Theorem can be used to find the length of the hypotenuse in a right triangle.

Questions & Answers

Q: What do the letters soh cah toa represent in trigonometry?

In trigonometry, soh cah toa represents the mnemonic used to remember the definitions of trigonometric functions: sine equals opposite divided by hypotenuse (soh), cosine equals adjacent divided by hypotenuse (cah), and tangent equals opposite divided by adjacent (toa).

Q: How do you find the cosine of an angle in a right triangle?

To find the cosine of an angle in a right triangle, you use the definition from cah in soh cah toa. Cosine equals the length of the adjacent side divided by the length of the hypotenuse. By identifying the adjacent side and using the Pythagorean Theorem, you can determine the cosine.

Q: How is the sine of an angle in a right triangle calculated?

The sine of an angle in a right triangle is found using the definition from soh in soh cah toa. Sine equals the length of the opposite side divided by the length of the hypotenuse. By identifying the opposite side, you can directly calculate the sine.

Q: How can the length of the hypotenuse be determined if it's not given?

If the length of the hypotenuse is not given, you can use the Pythagorean Theorem. By squaring the lengths of the other two sides and summing them, you can find the square of the hypotenuse. Taking the square root of this value gives you the length of the hypotenuse.

Summary & Key Takeaways

• This content explains how to find the cosine and sine of an angle in a right triangle.

• The definitions of trigonometric functions (soh cah toa) are used to determine the adjacent side or opposite side to the angle.

• The Pythagorean Theorem is used to find the length of the hypotenuse if it is not given.