• Congratulations to the Class of 2024 on your results!
    Let us know how you went here
    Got a question about your uni preferences? Ask us here

Rationalising the denominator (1 Viewer)

Shazer2

Member
Joined
Feb 16, 2012
Messages
439
Gender
Male
HSC
2013
Alright, so I have the following question.

1/root5+root2 + 3/3root2-root5

I then get

1(3root2-root5)/(root5+root2) + 3(root5+root2)/(3root2-root5)(root5+root2)

Then

3root2-root5+3root5+3root2/(root5+root2)(3root2-root5)

Then

3root2-root5+3root5+3root2/3root10-5+6-root10

And I finally got to

3root2-root5+3root5+3root2/2root10+1

This is completely the wrong answer, but if someone can guide me from the original question (preferably using LaTeX, as I don't know how, that would be much appreciated.)
 

Lemiixem

Member
Joined
Nov 14, 2011
Messages
44
Gender
Male
HSC
2012
1/root5+root2 + 3/3root2-root5

= 1(Root5 - Root2)/(Root5+Root2)(Root5-Root2) + 3(3Root2+Root5)/(3Root2-Root5)(3Root2+Root5)

= (Root5-Root2)/3 + (9Root2+3Root2)/13

= ( 13(Root5-Root2) + 3(9Root2+3Root2) )/ 39

= (13Root5-13Root2+27Root2+9Root2)/39

= (13Root5+23Root2)/39
 

pokka

d'ohnuts
Joined
Nov 4, 2011
Messages
312
Gender
Female
HSC
2011
1/root5+root2 + 3/3root2-root5

= 1(Root5 - Root2)/(Root5+Root2)(Root5-Root2) + 3(3Root2+Root5)/(3Root2-Root5)(3Root2+Root5)

= (Root5-Root2)/3 + (9Root2+3Root2)/13

= ( 13(Root5-Root2) + 3(9Root2+3Root2) )/ 39

= (13Root5-13Root2+27Root2+9Root2)/39

= (13Root5+23Root2)/39
I think your expansion of the numerator in 2nd fraction from 2nd to 3rd line should be "9Root2+3Root5"
 

pokka

d'ohnuts
Joined
Nov 4, 2011
Messages
312
Gender
Female
HSC
2011
You type in codes in something called LaTex form (you can use the program "Online Latex Equation Editor" to test it out) and different codes correspond to a different symbol. If you want to post it here you put the code between "[ tex ]" and "[ /tex ]" (just without the spaces of course). For example: To do square root of 5 just type [ tex]\sqrt 5[ /tex] (but without the spaces) then it will give you . Learning and typing some of these codes for maths solutions can take some time to become used to so yeh :)
 

Shazer2

Member
Joined
Feb 16, 2012
Messages
439
Gender
Male
HSC
2013
I was wondering how to type LaTeX, thanks pokka.

I also got the answer myself, thanks :)

TESTING:
 
Last edited:

Users Who Are Viewing This Thread (Users: 0, Guests: 1)

Top