pka
Elite Member
- Joined
- Jan 29, 2005
- Messages
- 11,976
Do you understand that n<SUP>2</SUP>=(n)(n)?
Then n<SUP>3</SUP>=(n)(n)(n), right?
6<SUP>2</SUP>=(6)(6)=36, right.
Thus 36 is a perfect square.
{1,4,9,16,25,49,64,81} is the set of perfect squares less than 100.
But 100 is also a perfect square: (10)(10).
So you see 96 is not a perfect square.
There is no whole number such that (n)(n)=96.
The symbol \(\displaystyle \sqrt n\) stands for a real number such that \(\displaystyle \left( {\sqrt n } \right)^2 = n\).
You see the square root is ‘sort of the reverse’ of the square.
\(\displaystyle \sqrt 1 = 1,\quad \sqrt 4 = 2,\quad \sqrt {49} = 7,\quad \sqrt {64} = 8\)
But \(\displaystyle \sqrt {98}\) cannot equal a whole number because 98 is not a perfect square.
However, \(\displaystyle \sqrt {98} = \sqrt {2\left( {49} \right)} = \left( {\sqrt {49} } \right)\left( {\sqrt 2 } \right) = 7\sqrt 2 .\)
So we factor the number, find the greatest perfect square in it.
Say 108=(2)(58) but neither of those is a perfect square.
It is true that 108=(4)(27). Oh 4 is a perfect square.
BUT 108=(3)(36) and 36 is an even greater perfect square.
So \(\displaystyle \sqrt {108} = \sqrt {36} \sqrt 3 = 6\sqrt 3 .\)
Then n<SUP>3</SUP>=(n)(n)(n), right?
6<SUP>2</SUP>=(6)(6)=36, right.
Thus 36 is a perfect square.
{1,4,9,16,25,49,64,81} is the set of perfect squares less than 100.
But 100 is also a perfect square: (10)(10).
So you see 96 is not a perfect square.
There is no whole number such that (n)(n)=96.
The symbol \(\displaystyle \sqrt n\) stands for a real number such that \(\displaystyle \left( {\sqrt n } \right)^2 = n\).
You see the square root is ‘sort of the reverse’ of the square.
\(\displaystyle \sqrt 1 = 1,\quad \sqrt 4 = 2,\quad \sqrt {49} = 7,\quad \sqrt {64} = 8\)
But \(\displaystyle \sqrt {98}\) cannot equal a whole number because 98 is not a perfect square.
However, \(\displaystyle \sqrt {98} = \sqrt {2\left( {49} \right)} = \left( {\sqrt {49} } \right)\left( {\sqrt 2 } \right) = 7\sqrt 2 .\)
So we factor the number, find the greatest perfect square in it.
Say 108=(2)(58) but neither of those is a perfect square.
It is true that 108=(4)(27). Oh 4 is a perfect square.
BUT 108=(3)(36) and 36 is an even greater perfect square.
So \(\displaystyle \sqrt {108} = \sqrt {36} \sqrt 3 = 6\sqrt 3 .\)