+0

# -9/0=?

0
1015
5

-9/0=?

Jun 11, 2014

#4
+102430
+5

$${\mathtt{\,-\,}}{\frac{{\mathtt{9}}}{{\mathtt{0.1}}}} = -{\mathtt{90}}$$

$${\mathtt{\,-\,}}{\frac{{\mathtt{9}}}{{\mathtt{0.01}}}} = -{\mathtt{900}}$$

$${\mathtt{\,-\,}}{\frac{{\mathtt{9}}}{{\mathtt{0.001}}}} = -{\mathtt{9\,000}}$$

$$\frac{-9}{n}\quad \mbox{ approaches} -\infty \mbox{ as n }\rightarrow\: ^+0$$

BUT n can approach 0 from above or below.

$${\mathtt{\,-\,}}{\frac{{\mathtt{9}}}{-{\mathtt{0.1}}}} = {\mathtt{90}}$$

$${\mathtt{\,-\,}}{\frac{{\mathtt{9}}}{-{\mathtt{0.01}}}} = {\mathtt{900}}$$

$${\mathtt{\,-\,}}{\frac{{\mathtt{9}}}{-{\mathtt{0.001}}}} = {\mathtt{9\,000}}$$

This time

$$\frac{-9}{n}\quad \mbox{ approaches} +\infty \mbox{ as n }\rightarrow\: ^-0$$

n cannot approach -infinity and +infinity at the same time and end up at the same place so -9/0 must be undefined.  I think indeterminant is the more common term these days but to the best of my understanding both terms mean the same thing.

Does that make sense to you?

Jun 12, 2014

#1
+3450
0

-9/0

-9/1 ÷ 0/0

-9/1 * 0/0

-0/0

= 0

I'm not entirely sure if this is correct because I tried it on two different calculators. One said ERROR and the other one said -Infinity.

...?

Jun 11, 2014
#2
+259
0

-9/0 = -infinity

Jun 11, 2014
#3
+5

Any number divided by 0 (zero) is undefined. This includes 0/0.

It is NOT infinity nor negative infinity.

The calculator that returned "-Infinity" is wrong!

Jun 12, 2014
#4
+102430
+5

$${\mathtt{\,-\,}}{\frac{{\mathtt{9}}}{{\mathtt{0.1}}}} = -{\mathtt{90}}$$

$${\mathtt{\,-\,}}{\frac{{\mathtt{9}}}{{\mathtt{0.01}}}} = -{\mathtt{900}}$$

$${\mathtt{\,-\,}}{\frac{{\mathtt{9}}}{{\mathtt{0.001}}}} = -{\mathtt{9\,000}}$$

$$\frac{-9}{n}\quad \mbox{ approaches} -\infty \mbox{ as n }\rightarrow\: ^+0$$

BUT n can approach 0 from above or below.

$${\mathtt{\,-\,}}{\frac{{\mathtt{9}}}{-{\mathtt{0.1}}}} = {\mathtt{90}}$$

$${\mathtt{\,-\,}}{\frac{{\mathtt{9}}}{-{\mathtt{0.01}}}} = {\mathtt{900}}$$

$${\mathtt{\,-\,}}{\frac{{\mathtt{9}}}{-{\mathtt{0.001}}}} = {\mathtt{9\,000}}$$

This time

$$\frac{-9}{n}\quad \mbox{ approaches} +\infty \mbox{ as n }\rightarrow\: ^-0$$

n cannot approach -infinity and +infinity at the same time and end up at the same place so -9/0 must be undefined.  I think indeterminant is the more common term these days but to the best of my understanding both terms mean the same thing.

Does that make sense to you?

Melody Jun 12, 2014
#5
+259
0

Ooooops I must be confusing with this $$\lim\limits_{x \to 0}{\frac{c}{x}} = \infty$$  $$c = const$$. Really sorry, I'm just hooked on maths analysis recently.

Jun 12, 2014