maths help please (1 Viewer)

[wantingtoknow]

Simplify sqrt(7 + 4sqrt3). Show working please, thanks !

 

[SpiralFlex]

We need to prove the general form of a nested radical.




[HR][/HR]Proof of form[HR][/HR]

Let



Squaring,



By the equality of surds,














(1) into (2)




[HR][/HR]Use of form[HR][/HR]


Now if we have a look at our form, we can see that



Substitute this into either equations, you will get the same result only reversed.





Hence,

 

[wantingtoknow]

oh my...that looks rather complex :S did you start off with the correct surd? how do I use your program to set out my question?

 

[SpiralFlex]

oh my...that looks rather complex :S did you start off with the correct surd? how do I use your program to set out my question?

http://www.codecogs.com/latex/eqneditor.php

Use the editor, copy, paste.

[.tex] (To beginning of code, no full stop.)

[/.tex] (To end of code, no full stop.)

 

[wantingtoknow]

lol okies thanks. are there no alternative working? this is for a year 9 person :S

 

[SpiralFlex]

lol okies thanks. are there no alternative working? this is for a year 9 person :S

I will check my brain for alternatives. Let me think for 5 minutes and I will get back to you. These types are nested radicals. Is your student using the Cambridge textbook? (This appeared in the extension section?)

 

[wantingtoknow]

this appeared in the middle of her homework booklet, so it can't be that difficult lol. it's the one and only question I can't figure out ._.

 

[SpiralFlex]

this appeared in the middle of her homework booklet, so it can't be that difficult lol. it's the one and only question I can't figure out ._.

My little brain is not capable of much but I will think of an easier way.

 

[SpiralFlex]

Got an easier method.

 

[SpiralFlex]

Easier method.

 

[wantingtoknow]

hm, how did you get from third line to fourth? ;-;

 

[Drongoski]

 

[SpiralFlex]

hm, how did you get from third line to fourth? ;-;

Perfect square.



I just had it in the form.

So,

 

[wantingtoknow]

OHHHHHHHHH, I SEE IT!!! THANK YOU SO MUCH, GUYS

 

[SpiralFlex]

OHHHHHHHHH, I SEE IT!!! THANK YOU SO MUCH, GUYS

I am scared of lightning....Help! My night light is flickering on and off....

 

[wantingtoknow]

lols ;O me too. going to switch my computer off now

 

[SpiralFlex]

lols ;O me too. going to switch my computer off now

Goodnight human.

 

[RealiseNothing]

There's a much easier way to do this question, will post in a sec.

 

[RealiseNothing]

Square both sides



The irrational parts must be equal



Simplify from here on





Hence and

So



First time using latex, please work.

 

[SpiralFlex]

There's a much easier way to do this question, will post in a sec.

Is what I and Drongoski did.