# lovely maths

Discussion in 'General Discussion' started by xirokx, 7 Jun 2010.

1. xirokx

# Location: N.W London

i have two numbers i need to express in standard form, can someone tell me how?

a) sqrt3 (so in words surd of 3)

b) 1/5 sqrt5 (so in words 1over5 surd of 5)

thanks

2. D D Danneh

# Location: Sheffield

standard form? Sure you don't just mean index form?

3. Skillmister

# Location: Wales

Cant be standard form with those questions im sure

4. D D Danneh

# Location: Sheffield

That's what I was thinking, if it was index form though you'd be wanting:

a) 3^1/2

b) 1/5 5^1/2

5. Begbie

6. sid

# Location: London

multiply top and bottom by square root to get rid of them

Its called rationalising the denominator

7. PMKeates

# Posts: 14,052

How do you rationalise the denominator of sqrt(3)?

8. D D Danneh

# Location: Sheffield

There is no irrational denominator to rationalise

9. agnes

# Location: Amsterdam, NL

I wish I knew the answers, I would be earning so much money if so.

ags

10. Alex74

= 5^(-1/2)

11. xirokx

# Location: N.W London

yep i meant index form...

sowwwwyy

yeh so like 1.3734242x102 (10 the power of 2)

12. lord filbuster

# Posts: 1,406

That is standard form.

500 = 5x10^2
1000 = 1x10^3 etc.

As above, you can't write irrational numbers like sqrt(3) in standard form.

You must want them written in index form, as the others have given you.
sqrt(3) = 3^1/2
1/5*sqrt(5) = 1/5*5^-1/2

13. xirokx

# Location: N.W London

can you write these using the proper symbols for me and not using words as I want to make sure I have this correct..

14. lord filbuster

# Posts: 1,406

ok, i can't work out how to do superscripts, so here is a picture:

15. xirokx

# Location: N.W London

i love u

16. Killerkebab

# Location: Kent

The bottom one is wrong - I thought he wanted 1/5 * sqrt(5), NOT 1/5 * 1/sqrt(5)

17. lord filbuster

# Posts: 1,406

Possibly, i just guessed at what he wanted. The OP is a bit ambiguous.

18. xirokx

# Location: N.W London

to clarify I need to convert both these numbers into index form, what would it be:

a) 1/5 * sqrt(5)

b) 7^6

thanks

19. Westyfield2

# Location: Bath

I tried to forget A-Level maths for a reason! Don't bring it all flooding back!

20. xirokx

# Location: N.W London

im sorry its my error there is no *

the question is : simplify 1/sqrt5 and leave answer in index form

my answer to the question which is not in index form is:

1/5 sqrt5

so my answer (1/5 sqrt5) now needs to be put in index form

third time lucky