Question

multiply:

Answer 1

2*8 = 16

Answer 2

\[\sqrt{7} * \sqrt{3}\]

Answer 3

It won't load correctly.

Answer 4

sqrt(7) * sqrt(3)

Answer 5

Okay, so there's this rule that says
\(\Large \sqrt{a}*\sqrt{b} = \sqrt{a*b}
Basically, you can bring them together.

Answer 6

\(\Large \sqrt{a}*\sqrt{b} = \sqrt{a*b}\)'
Closed tag.

Answer 7

Well, I didn't know. Lol. so they just multiply together?

Answer 8

\[\sqrt{7 } \times \sqrt{3} = \sqrt{7\times3} = \sqrt{21}\]

Answer 9

Yes. Now, you should look to see if it can be simplified from there. Is 21 a perfect square? Are there any perfect square factors?

Answer 10

I don't think so.

Answer 11

Can \(\sqrt{21} \) be simplified further now?

Answer 12

Nope =) It's as simple as it can be.

Answer 13

yeah it can be simplified

Answer 14

Haha whut

Answer 15

Satellite got me questionin' my knowledge.

Answer 16

\[\large \sqrt{21}=\sqrt{7}\times \sqrt{3}\]

Answer 17

ahahahaha

Answer 18

lol

Answer 19

You frickin' goofball.

Answer 20

point being that there is no such mathematical operation as "simplify"
you think \(\sqrt{21}\) is "simple" and i think \(\sqrt{7}\times \sqrt{3}\) is simple
it is a matter of taste

Answer 21

Now I'm confused.. lol.

Answer 22

@Mikeyy1992 ignore me i am making a point, but don't let me confuse you \(\sqrt{21}\) is the correct answre

Answer 23

I agree with you, Satellite. Rewrite is a better term for it.

Answer 24

fluttering i think

Answer 25

Yes. It means fluttering.

Answer 26

@satellite73... very smart yet quite humorous.

Answer 27

Haha quite smart. Smart enough that when he said it could be simplified, I was convinced enough to try and find a perfect square factor.

Answer 28

*doesn't close question, just to watch everyone talk* Lol :P

Answer 29

well really
if you were asked to "simplify" wouldn't
\(\sqrt{6400}\) be simpler if first you wrote it as \(\sqrt{64}\times \sqrt{100}\) ?

Answer 30

Yes, certainly. Kind of.

Answer 31

good point Satellite. But some teachers, people, students say refer it as "simplify", but idk, simply depends on the person.

Answer 32

"Simplify" is just a very poorly defined term.

Answer 33

when i am king of the math teachers i will banish the word "simplify" from their vocabulary
is \(\frac{1}{3}\) simpler than \(\frac{4}{12}\)? no not if i want to add \(\frac{1}{3}+\frac{7}{12}\) it isn't

Answer 34

You aren't king of the math teachers yet?

Answer 35

i have seen questions that say "simplify" \(2x(x+3)\) when it is clear it means "multiply"

Answer 36

well your kinda already the "king of math teachers" here on OS lol

Answer 37

When I succeed you as king of the math teachers, I'll ban teaching the "distance formula." And just make sure people actually understand the Pythagorean theorem and how to use it.

Answer 38

amen to that as well

Answer 39

also on my hit list is "cancel"

Answer 40

reduce to 1?

Answer 41

sometime the \(x\) cancels in \(x^2+x-x-1\)

Answer 42

sometimes it cancels in \(\frac{x^3}{x^2}=x\)

Answer 43

SmoothMath, lol why would you ban teaching the "distance formula", just curious on your thought.

Answer 44

sometimes cancelling means \(\sqrt{x^2}=x\)

Answer 45

i have even heard "cancel" as in \(e^{\ln(x)}=x\)

Answer 46

adds to zero
reduce to lowest terms
compose a function with its inverse

Answer 47

if you call the damn thing what it is, there will be infinitely less confusion

Answer 48

and now i will go take my valium

Answer 49

So the way we're told to teach kids to find the distance between two points is: "Use the distance formula."
There are a number of things wrong with this:
1) They have to actually MEMORIZE the distance formula. Most of them won't, and even if they do, memorization and regurgitation is the lowest form of learning.
2) It encourages them to follow a formulaic, procedural way of solving the problem instead of actually THINKING.
3) By the time they get to this in Geometry, they already HAVE all the tools they need to solve this problem. In fact, it's ONE tool, and it's the Pythagorean theorem. The distance formula IS the pythagorean theorem, so we're making them learn it AGAIN, except in a more complicated looking form.