The Student Room Group

Quick simplifying surds question!

Need help on how this = this

I uploaded a pic.

ImageUploadedByStudent Room1414585226.626652.jpg

Why does the 3 remain there? Cannot seem to figure out how it works. Any help will be appreciated.

Thanks,



Posted from TSR Mobile
Original post by Jelly150
Need help on how this = this

I uploaded a pic.

ImageUploadedByStudent Room1414585226.626652.jpg

Why does the 3 remain there? Cannot seem to figure out how it works. Any help will be appreciated.

Thanks,



Posted from TSR Mobile


213=219\displaystyle \frac{\sqrt{21}}{3}=\sqrt \frac{21}{9}
Reply 2
Original post by skyakdu
√21 = √(3*7) = (√3)*(√7)

(√7)*(√3) / 3 = (√7) * (1/√3) = √7/√3 = √(7/3)

Posted from TSR Mobile


Thanks for help, but don't understand how root3/3 = 1/root3

I understood what Mr M explained and managed to get the right answer. Hhaa


Posted from TSR Mobile
Reply 3
Original post by Mr M
213=219\displaystyle \frac{\sqrt{21}}{3}=\sqrt \frac{21}{9}


Thanks!


Posted from TSR Mobile
Reply 4
Original post by Jelly150
Thanks for help, but don't understand how root3/3 = 1/root3

I understood what Mr M explained and managed to get the right answer. Hhaa

Edit - I understand how that works!

Anyway, thanks!
Posted from TSR Mobile





Posted from TSR Mobile

Quick Reply

Latest