CAHSEE Math 2.2 Mathematical Reasoning

Mathematical Reasoning: Drill Set 2, Problem 2. A positive integer, n, when squared, is always greater than or equal to the doubling of n, except when n equals...what?

CAHSEE MathMathematical Reasoning
Exponents and RadicalsInteger Exponents
LanguageEnglish Language
Mathematical ReasoningGeneralizing results

Transcript

00:24

see whether we can conceive the theory of n in our brain.

00:29

When we get these kinds of problems, always

00:31

try 0 first because it's usually really easy to manipulate.

00:35

Then 1. Then negative 1. Then a fraction. Annnnnd we're done. Usually.

00:41

In this case, note the word ALWAYS and greater than or equal to...

00:45

It's giving us the equation n squared is greater than or equal to 2n.

00:50

True for 0. True for 2. True for 4. True for one half? No.

00:55

Try 1. Well, 2n is 2 and 1 squared is...1. So it's the only one that's NOT true --

01:05

And the answer is A.