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Can anyone please explain why it is negative?

My understanding is -3^2=-3x-3........which should equal positive 9...

What is the difference between the above and (-3)^2?

I am obviously missing something, please help!!

Thanks so much!!

2007-06-20 12:06:05 · 8 answers · asked by Rebirth _2007 1 in Science & Mathematics Mathematics

Please, if you can, try to explain -4^-2 (why is it = to -1/16?) and 4^-2 (why is it equal to 1/16?).

Thanks again!

2007-06-20 12:11:12 · update #1

8 answers

When you write -x^2 you mean -(x^2)

In the same way -3^2 means -(3^2) = -9

(-3)^2 is 9 and (-x)^2 = x^2

-------------------------------

-4^-2
means
-(4^(-2))
= -(1/(4^2))
= -1/16

2007-06-20 12:10:14 · answer #1 · answered by gudspeling 7 · 0 0

-3^2 written without brackets means -(3^2), and not (-3)^2.
The first is equal to -9, and the second to 9.

This is a straightforward application of the principles embodied in the mnemonic PEMDAS, which indicates order of operations in mathematical expressions. Exponentiation precedes subtraction.

2007-06-20 19:14:00 · answer #2 · answered by Anonymous · 0 0

(-3)^2 = (-3) x (-3) = 9

-(3)^2 = (-1) x (3)^2 = (-1) x 9 = -9

2007-06-20 19:10:50 · answer #3 · answered by Zaheer 1 · 0 0

It's because of order of operations.

-3^2 = -9, BUT

(-3)^2 = 9

Think of the first part in this way:

- (3 * 3), which is the same as (-1)(3 * 3), or (-1)(9), or -9.

Think of the second equation in this way:

(-3)^2 = (-3)*(-3)

Which is, of course, 9.

2007-06-20 19:11:56 · answer #4 · answered by Puggy 7 · 1 1

In the hierarchy of mathematical operations exponentiation comes before negation. So it should be interpreted as:

-(3^2) = -9

2007-06-20 19:11:45 · answer #5 · answered by Northstar 7 · 0 0

No, -3^2 means -(3^2).

2007-06-20 19:09:50 · answer #6 · answered by Anonymous · 2 0

-(3²)=-9
(-3)²=+9
when written -3² it is assumed that the ² only applies to the 3, not the -

The difference is between -3*3=-9 & (-3)(-3)=9

2007-06-20 19:13:22 · answer #7 · answered by yupchagee 7 · 0 1

BODMAS

indices (coming under other) comes before multiply

the - sign means x-1

2007-06-20 19:11:37 · answer #8 · answered by SS4 7 · 0 0

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