NEED to know to PASS ALGEBRA - How To Fix This (not allowed) 

To say that dividing by a radical is "not allowed" is misleading if not downright false. There are few operations in mathematics that are "not allowed." Division by zero is not allowed. Taking the square root of a negative number is "not allowed" (if the answer must be real.) But dividing by a radical? The only arithmetic reason for avoiding division by a radical is that in the old days this was tough to do by hand. For the last forty years we have had calculators to do the arithmetic. It makes no difference to a calculator if you enter a division problem where the divisor is a radical. The answer is calculated to the same precision as any other (non-exact) division. Of course, there are good algebraic reasons for knowing how to rationalize a denominator. But to tell students that a radical in the denominator is "not allowed" is misleading at best.

Why is dividing by an irrational any worse than multiplying by an irrational? Does it have something technical to do with the logical definition of division?

I enjoy your videos - they are very helpful and I've learned a few things. I would have loved to have had this kind of help back in the 70's when taking Algebra 1 and 2 in high school but back then, teachers just looked at you funny and thought to themselves you were stupid if you said you didn't understand.

Not really sure why it is okay to have an irrational number in the numerator, but not okay to have an irrational number in the denominator. Whether the irrational number is in the denominator or in the numerator, the end result will still itself be irrational.

I am an adult ( or I least I claim to be) who enjoys learning math. Could someone explain to me the point of rationalising the denominator? The result was 4 sqrt3/3 which is still not rational, So I am a bit confused. Thanks!

#rationalize #rationalization #rationalizing #rootrationalization #rootrationalizing

(4√3)/3

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Why is the square root of 16/3 not the most simple solution?

Not allowed in algebra.... HOWEVER, In every other higher math class, nobody gives a damn. Seriously. I was working with a kid and her precalc teacher made her rationalize the denominator and I was just confounded as to why? There's no real purpose. Same value

Irrational numbers

Irrational denominators

Root(16/3)

It's called rationalizing the denominator.

Ok, after 3 minutes of advertisements I give. Being old, I find 4 divided by the same root of 3. Ads still going on. Won't be back

It starts from false premises about what is not allowed in algebra and then ... "much ado about nothing" , too much ado!

Not allowed? Says who? And is this algebra? It is certainly allowed over here so I assume it is a 'rule' in the US?

Doesn't make sense to me. The kid went through the algebra and solved the equation, got the right answer, and points are lost? I've taught Pre-K through 20 (doctoral) and taught many courses in math, algebra, physics, engineering and never came across this. While I might do this just to clean up my answer and make it look "pretty", if I had this formula loaded into a math program such as Mathcad or MatLab, I'd leave it and let the computer deal with it. On the other hand, I do a lot of heavy computing, Fourier series, Bessel functions, Gamma functions, Laplace transforms, Heaviside functions - it wouldn't bother me one bit to drop an integral or a differential into a denominator. You'll see that in many papers. To heck with a square root. Who cares.

Let me see what you offer free .