# Math Help - Surds

1. ## Surds

NO calculator allowed.

How can i make the top answer to a surd?

Thanks

2. Originally Posted by r_maths
NO calculator allowed.

How can i make the top answer to a surd?

Thanks
sqrt[1200 - 400sqrt(2)]

factor out 400 out of what's under the squareroot, we get:

sqrt[400(3 - sqrt(2))]

now the squareroot of a product = the product of the squareroots, so

= sqrt(400)*sqrt(3 - sqrt(2))
= 20*sqrt(3 - sqrt(2)) ..............the sqrt(400) = 20

3. thanks

4. Originally Posted by r_maths
thanks
sure thing

by the way, the "math thing" isn't working at the moment. this site uses LaTex, and the system is currently down