From the course: Test Prep: GRE

Unlock the full course today

Join today to access over 23,200 courses taught by industry experts.

Cube and fourth roots

Cube and fourth roots

From the course: Test Prep: GRE

Start my 1-month free trial Buy for my team

Cube and fourth roots

“

- [Voiceover] So the final thing I want to cover in arithmetic is cube and fourth roots. So cube roots look like this. So if I said the cube root of 27, this is just telling you what times what times itself again will give me 27. The answer is 3. Because 3 times 3 is 9 times 3 again is 27. So kind of a unique thing about cube roots compared to square roots we can do a cube root of a negative number. What about the cube root of negative 27? Well that would be negative 3 because if you negative 3 times negative 3, you're going to get 9 then if you multiply it by negative 3 again you get negative 27. So you can actually take a cube root of a negative number. So another thing, kind of similar to cube roots is fourth roots. And we don't really see this kind of stuff a ton on the GRE but I just want you to know what it is just in case you do. The fourth root means a number times itself four times would get that number. So the fourth root of 16 is 2 because 2 times 2 times 2 times 2 is 16…

Contents