ACT Math Pre-Algebra Drill 1, Problem 3. Can you find the product of two square roots?
|Foreign Language||Arabic Subtitled|
|Pre-Algebra||Square roots and approximations|
Square roots of numbers
|Product Type||ACT Math|
We'll rarely be asked to calculate a square root that doesn't come out even on a test like this...
...so if we feel like we've been backed into that corner of actually having to calculate it...
...we may have messed up somewhere upstream.
That's not to say they won't ever throw a weird one in there,
but... it's just something to keep in mind.
So, in this case we have to think about the factors
of 32... 2 and 16 and 4 and 8.
First we have the square root of 32. What perfect squares go into 32 evenly?
Well, 4 does... but the bigger the better, in this case anyway...
16 times 2 equals 32, and 16 is 4 squared.
So we can rewrite this as the square root of 16 times 2, then we can pull out a 4 to
make it 4 square root of 2.
Next on the docket is the square root of 8. Now 4 is the best we can do.
The square root of 4 times 2 can be rewritten as 2 square root of 2.
When we multiply these two together, we get 4 times 2 is 8...
...and then square root of 2 times square root of 2 is... 2.
Multiply those two numbers together, and we're left with 16...
So the answer C.
As in, "Calculating villains."