From the course: Test Prep: GRE

Unlock the full course today

Join today to access over 22,600 courses taught by industry experts or purchase this course individually.

Cube and fourth roots

Cube and fourth roots

From the course: Test Prep: GRE

Start my 1-month free trial

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