Solving a Basic Trigonometry Doubt: Where to Learn?

In summary, the conversation is about a basic trigonometry doubt and a request for a website to learn more about it. The expert suggests using the formula cos(x-y)=cos(x)cos(y) + sin(x)sin(y) to solve the equation 3cos2t + 4sin2t = 5cos(2t-53.13degrees). They also provide a website, http://www.ping.be/~ping1339/index.html#Main-Purpose-=-MATH- [Broken], for further learning.
  • #1
skan
15
0
I have basic trignometry doubt

how to u get 5cos(2t-53.13degrees) from 3cos2t + 4 sin2t.

Can someone suggest a site from where I can lean basic trinometry

thanks.
skan
 
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  • #2
well, nice question...
use cos(x-y)=cos(x)cos(y) + sin(x)sin(y).

3cos2t + 4sin2t = 3(cos2t + (4/3)sin2t). The trick is to define 4/3 = tan(y)=siny/cosy where y = 53,13°. Now you have 3(cos2t + (siny/cosy)sin2t). or this becomes following expression : (3/cosy)(cosy * cos2t + siny * sin2t) =
(3/cosy)cos(2t - 53.13°) and cosy = cos(53.13°) = 0.6

3/cosy = 3/0.6 = 5

problem solved

regards
marlon
 
  • #3
Check out this site...


http://www.ping.be/~ping1339/index.html#Main-Purpose-=-MATH- [Broken]

marlon
 
Last edited by a moderator:
  • #4
Thanks a lot for the answer and the great link!
 

1. Where can I find resources to learn basic trigonometry?

There are many resources available for learning basic trigonometry, including textbooks, online courses, and educational websites. Some popular options include Khan Academy, MathIsPower4U, and Coursera. You can also check with your local library or school for additional resources.

2. How long does it take to learn basic trigonometry?

The time it takes to learn basic trigonometry will vary depending on your prior knowledge and learning style. It typically takes a few weeks to cover the basics, but it may take longer if you need to review foundational concepts or if you are learning at a slower pace.

3. Do I need to know algebra before learning trigonometry?

While it is helpful to have a basic understanding of algebra before learning trigonometry, it is not always necessary. Many introductory trigonometry courses will review necessary algebraic concepts as they are needed. However, having a strong foundation in algebra will make it easier to grasp trigonometric concepts.

4. What are the most important concepts to understand in trigonometry?

Some of the most important concepts in trigonometry include the trigonometric functions (sine, cosine, and tangent), right triangle trigonometry, and the unit circle. It is also important to understand how to use trigonometric identities and solve trigonometric equations.

5. Can I use a calculator to solve trigonometry problems?

Yes, a calculator can be a useful tool for solving trigonometry problems. However, it is still important to understand the underlying concepts and be able to solve problems by hand. Additionally, some exams or tests may not allow the use of a calculator, so it is important to be able to solve problems without one as well.

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