So you guys know perfect squares, right?
Like 4 is a perfect square because 2 x 2 = 4.
25 is perfect, 196 is perfect, 1 000 000 is perfect...
How do you know if a number is a perfect square you ask?
Well, you have to memorize. That's the only way.
Nah, I'm kidding. You have to find the factors of that number, find out if the primes can divide into two equal groups, and multiply.
Here's an example, because I love examples:
Blah, blah, blah, insert lesson about writing radicals in different ways.
By the way, if you see:
Then you cancel the 2 and the radical sign, and the square root is x.
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Anyways, now comes the grade 10 part. A new "sign" is introduced:
If you see this, that means you need to find a cube root.
Instead of square roots where it was 8 x 8 = 64, now it's 4 x 4 x 4 = 64.
Instead of two numbers that are multiplied, it's three.
Here's a list of perfect cubes:
Basically you use the same rules as you would do for square roots.
When finding out factors, you need to have equal groups of 3, not two.
Now, how do you find a square/cube root of a decimal?
 |
| Convert to a fraction. |
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| Find the factors/roots. |
Then just convert the root into a decimal again.
The square root of 0.0009 is 0.03.
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*Insert instructions to how to find the root of a cube or square NOT using a calculator*
There are apparently many ways to do this, so here's a site showing plenty of methods.
http://www.murderousmaths.co.uk/books/sqroot.htm
Other than that, I should really be studying for my quiz so bye!
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By the way, something new that came up in my homework: there's an irrational number/symbol.
It's "e" and it's 2.71... According to Wikipedia, it's "Euler's number".
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