Maths... Is this valid?

[Laniakea]

Soo I have solved a trigonometry question on youtube to test myself and find an awnser, then I watched how the teacher solved it and it was slightly diffrent than mine so he got the awnser:

(3 + sqrt(3)) / 6

Where I got

(1 + sqrt(3)) / (2 . sqrt(3))

 

Sooo which one is valid in an exam and which one is the you know, last version, most simplified version. How can I simplify it? And thanks

[Jurrunio]

Yours is invalid in examination becase the denominator (number below the line) cannot contain irrational numbers like sqrt(3).

 

Simplify it by multiplying both denominator and numerator (number above and below) by the demoniator (2.sqrt(3) in this case). Then divide their common factor if possible.

[Laniakea]

Just now, Jurrunio said:

Yours is invalid in examination becase the denominator (number below the line) cannot contain irrational numbers like sqrt(3).

 

Simplify it by multiplying both denominator and numerator (number above and below) by the demoniator (2.sqrt(3) in this case). Then divide their common factor if possible.

Thank you man, you now taught me that denominators cannot be irrational and saved my life. Love you thatnks!

[hardtofindinthefuture]

Quicc mafs

[Enderman]

The answer is the same.

Making the denominator a rational number just makes it look better.

I've never seen a teacher take marks off because of something like that, since both are the correct answer.

[-TesseracT-]

1 hour ago, Jurrunio said:

Yours is invalid in examination becase the denominator (number below the line) cannot contain irrational numbers like sqrt(3).

 

 

why tf would it be invalid

[Jurrunio]

17 minutes ago, -TesseracT- said:

why tf would it be invalid

 

[Jurrunio]

1 hour ago, Enderman said:

The answer is the same.

Making the denominator a rational number just makes it look better.

I've never seen a teacher take marks off because of something like that, since both are the correct answer.

My school would. Probably different education scheme in different countries.

[Enderman]

Just now, Jurrunio said:

My school would. Probably different education scheme.

Are you in the US?

[Jurrunio]

3 minutes ago, Enderman said:

Are you in the US?

Nope. I got my high school education in Hong Kong

 

So asians are indeed better at math because we dont like messy answers.

[Enderman]

1 hour ago, Jurrunio said:

Nope. I got my high school education in Hong Kong

 

So asians are indeed better at math because we dont like messy answers.

I'm not in the US either.

You'll learn once you get to university that having irrational numbers in the denominator is not bad and often cannot be avoided.

[Jurrunio]

5 minutes ago, Enderman said:

I'm not in the US either.

You'll learn once you get to university that having irrational numbers in the denominator is not bad and often cannot be avoided.

So avoid when possible.

 

moving rational numbers around is much better than irrational numbers when it comes to finding unknowns.

[Enderman]

14 minutes ago, Jurrunio said:

So avoid when possible.

 

moving rational numbers around is much better than irrational numbers when it comes to finding unknowns.

When finding unknowns you don't move numbers around, you move variables

Numbers only go in at the last step.

[Jurrunio]

24 minutes ago, Enderman said:

When finding unknowns you don't move numbers around, you move variables

Numbers only go in at the last step.

when varibales and unknowns are botched together as a multiplier...

 

for example, sqrt(2).a = sqrt(3).b. Taking away the sqrt from the denominator makes further calculations after applying a = sqrt(6).b/2 to other equations less annoying (as if long algebra isnt annoying enough)

[Enderman]

7 minutes ago, Jurrunio said:

when varibales and unknowns are botched together as a multiplier...

 

for example, sqrt(2).a = sqrt(3).b. Taking away the sqrt from the denominator makes further calculations after applying a = sqrt(6).b/2 to other equations less annoying (as if long algebra isnt annoying enough)

Idk what kind of math you're doing, but usually there aren't numbers inside the square roots.

It is just other variables.

This is why you only simplify on the last step.

[-TesseracT-]

2 minutes ago, Enderman said:

Idk what kind of math you're doing, but usually there aren't numbers inside the square roots.

It is just other variables.

This is why you only simplify on the last step.

what math are you doing?

[Enderman]

4 minutes ago, -TesseracT- said:

what math are you doing?

University...?

There's math in almost every course, whether it is electrical, thermodynamics, calc, etc

[-TesseracT-]

1 minute ago, Enderman said:

University...?

There's math in almost every course, whether it is electrical, thermodynamics, calc, etc

Yea ok. in my mechanics course (uni) you would have square roots (with "known numbers") all the time. Also in linear algebra I, Calculus I, II and III

[Jurrunio]

13 minutes ago, Enderman said:

Idk what kind of math you're doing, but usually there aren't numbers inside the square roots.

It is just other variables.

This is why you only simplify on the last step.

That's back in my high school days. I can say that the teachers are just making them complex so we dont end up having everyone scoring 90s to 100 marks in exams.

[Dash Lambda]

11 hours ago, Jurrunio said:

Yours is invalid in examination because the denominator (number below the line) cannot contain irrational numbers like sqrt(3).

It's not invalid, it's just not the form certain teachers prefer. It's the same number.

It can be an easier form to work with, but the more attention you pay to making sure your number is in a slightly neater form the less attention you're paying to the math.

 

11 hours ago, Enderman said:

I've never seen a teacher take marks off because of something like that, since both are the correct answer.

I had them in high school. Haven't had a professor care, though.

[Jurrunio]

11 minutes ago, Dash Lambda said:

It's not invalid, it's just not the form certain teachers prefer. It's the same number.

It can be an easier form to work with, but the more attention you pay to making sure your number is in a slightly neater form the less attention you're paying to the math.

In the public exam here (the one after high school ends), it is necessary or else the mark for correct answer will be deducted, just like leaving out the unit.

[Dash Lambda]

24 minutes ago, Jurrunio said:

In the public exam here (the one after high school ends), it is necessary or else the mark for correct answer will be deducted, just like leaving out the unit.

Well, I consider that a failing of the exam.

[HZapperz]

Correct me if im wrong but those seem to be 2 different answers. With the first one being equal to .788 and the second one being equal 2.36

[Laniakea]

46 minutes ago, HZapperz said:

Correct me if im wrong but those seem to be 2 different answers. With the first one being equal to .788 and the second one being equal 2.36

I tried it they both equal to .788.....

[Dash Lambda]

2 hours ago, HZapperz said:

Correct me if I'm wrong but those seem to be 2 different answers, with the first one being equal to .788 and the second one being equal to 2.36.

What are you entering into the calculator?

(1 + sqrt(3))/(2*sqrt(3)) = (sqrt(3)/sqrt(3))(1 + sqrt(3))/(2*sqrt(3)) = (sqrt(3) + 3)/(6)