[BlueBaron]

So, we started learning basic Trigonometry in school. So far, even though hard I managed to understand most of it. We have homework, I was able to successfully finish all tasks expect one:

I must find A= є?, If given Tangent is 36є. I did search on ****** but, it says "Use a calculator" Like I don't know how to. I found its inverse function, Arctan and the final answer is 88.40...є, but how do I find it on paper without the use of calculators.

Much appreciated

[DRUNKY]

You do need to use the calculator.

[Alphlax]

Is there a right angle?

[Mauzen]

So if I got that right you got one angle given as 36°?
No use for arctan then. Sum of all angles in a triangle is 180°. One is 90° when talking about trigonometry, ones 36°, so the last one is 180-90-36=54°.

In general, how to find arctan on paper?
as defined: tan alpha = a/b
So if (tan alpha) is given, just draw a line with whatever length, not too small to keep measure error small, and not too big to handle. This is your line b. Now choose an end of that line, and add line a in a right angle to it. The length of a should be your (tan alpha) * (your length of b).
At last connect the remaining line ends to get a triangle, and measure the angle in opposite of line a. Thats your (arctan alpha).

[[MM]IKKE]

Can you give us the exact question? A tangent is a number (radian), so I don't see how that tangent itself is a radian.

What's the context of the question? Have you studied series?

If yes, the formula to estimate the Arctan of something is:


I converted your angle to radians & filled in the formula, it gives a good result.
http://www.wolframalpha.com/input/?i...%3D0.628318531

This is not the solution you posted, so did you post the actual solution or did you post what you THINK is the actual solution?

Note that the exact solution matches pi/5, which might be related to something you studies before.

[Mauzen]

Quote:

Originally Posted by [MM]IKKE Can you give us the exact question? A tangent is a number (radian), so I don't see how that tangent itself is a radian. What's the context of the question? Have you studied series? If yes, the formula to estimate the Arctan of something is: I converted your angle to radians & filled in the formula, it gives a good result. http://www.wolframalpha.com/input/?i...%3D0.628318531 This is not the solution you posted, so did you post the actual solution or did you post what you THINK is the actual solution? Note that the exact solution matches pi/5, which might be related to something you studies before.

When beginning with trigonometry in school people almost always use degrees. Radians are barely used in school, even in later years. Also, arctan in calculators often offers trigonometric functions for radians and degrees. And thats what he did, arctan 36 in degrees is 88.4. Though I doubt that 36 should be a tangens value, but rather a given angle of the triangle (he also wrote 36°), as i wrote before. A tangens of 36 would be a rather uncommon triangle that rather looks like a line, and teachers stick to common forms to get people used to trigonometry. a 36°/90°/54° triangle would rather be a common form, than a 88.4°/90°/1.6° one.

[Forrest~]

Please no. I wanted to escape from math on the SA-MP forums, now I get to see that here too. *cries*

[Mauzen]

Quote:

Originally Posted by Forrest~ Please no. I wanted to escape from math on the SA-MP forums, now I get to see that here too. *cries*

If you want to escape maths, why do you read threads with "trigonometry" in the title then?

[Forrest~]

Quote:

Originally Posted by Mauzen If you want to escape maths, why do you read threads with "trigonometry" in the title then?

Good question. *attaches jetpack and dusts off*

[[MM]IKKE]

Quote:

Originally Posted by Mauzen When beginning with trigonometry in school people almost always use degrees. Radians are barely used in school, even in later years. Also, arctan in calculators often offers trigonometric functions for radians and degrees. And thats what he did, arctan 36 in degrees is 88.4. Though I doubt that 36 should be a tangens value, but rather a given angle of the triangle (he also wrote 36°), as i wrote before. A tangens of 36 would be a rather uncommon triangle that rather looks like a line, and teachers stick to common forms to get people used to trigonometry. a 36°/90°/54° triangle would rather be a common form, than a 88.4°/90°/1.6° one.

Degrees are easier to read & understand, but in the end, radians are a lot more useful when applying them to other parts of maths. We also mainly used them in highschool. By the way, made a mistake in my previous post, 36° equals pi/5, not the solution of the problem.

The weird triangle you described & the fact he equalled his tangent to a degree - I've honestly NEVER seen that before - made me ask him about the exact question Also, if the tangent is given in the question, then why would the solution be like you replied (just counting the angles all together)? Your answer isn't illogical, but then the question would be odd.

So let's wait for OP!

[cessil]

next time you have a problem, ask your teacher