Simplify the following:

EbenezerSon · 2014-08-30 04:13:39

bobbym wrote:

but remember the square root has a precise meaning. It only takes the positive answer.

Please, illustrate it with an example to clarify it.

bobbym · 2014-08-30 04:17:38

Normally you would say what number when multiplied by itself equals 9

Well 3 x 3 = 9 and (-3) x (-3) = 9 so why is it not

The reason is the √ operator or instruction means only the positive one so the first one is correct. There is more but it is jargon that you do not need right now.

EbenezerSon · 2014-08-30 04:26:36

What is "the operator or instruction" or you mean the instruction about root sign?

bobbym · 2014-08-30 04:33:03

This is what I mean √

EbenezerSon · 2014-08-30 20:44:32

Thanks Bobbym

I am having different answers with these;

Without using tables evaluate
(0.04)^-3/2 . I had 1/125 and the book has 125.

Again,

(0.64)-1/2 I had 4/5 and the book has 5/4 which is which?
Please confirm.

bobbym · 2014-08-30 21:21:01

Hi;

The book is right in both cases.

EbenezerSon · 2014-09-01 01:00:39

Ok, I see, but if you wouldn't mind could you copy both steps here to convince me?

Thank you

Last edited by EbenezerSon (2014-09-01 01:10:10)

bobbym · 2014-09-01 01:13:57

Hi;

Can you work the second one?

EbenezerSon · 2014-09-01 01:21:37

Unless you help because - I am now learning your steps

EbenezerSon · 2014-09-01 01:23:55

How did the 1/2 come?

Last edited by EbenezerSon (2014-09-01 01:32:54)

bobbym · 2014-09-01 01:33:12

(-3)(1/2) = (-3/2)

EbenezerSon · 2014-09-01 01:46:24

bobbym wrote:

(-3)(1/2) = (-3/2)

I see now - thank very much

I have similar problems here but I will try to solve.
Thanks once more.
I never knew you were just behind your machine

bobbym · 2014-09-01 01:52:43

I never knew you were just behind your machine

I do not understand.

Try the second one and post if you get stuck.

EbenezerSon · 2014-09-01 01:55:33

It seems my method here works
(4 * 10^-2)^-3/2
2^ -3* 10^6/2 = 125

bobbym · 2014-09-01 02:04:55

Whatever works for you is good.

EbenezerSon · 2014-09-01 02:06:18

=(0.64)^1/2
= (0.64^-1)1/2
= 1.5625^1/2
=1.25

bobbym · 2014-09-01 02:09:12

That is correct.

EbenezerSon · 2014-09-01 02:20:38

bobbym wrote:

I never knew you were just behind your machine
I do not understand.

You were offline when I was online, so before I realise you were online, that prompted me to say you were just behind your personal computer

Another one,

Find the value of X
3^3x - 3^x+1 - 3^x + 3 = 0

I couldn't solve

bobbym · 2014-09-01 02:31:02

You should use the substitution idea.

EbenezerSon · 2014-09-01 23:02:31

I normally, see something like 4x^2, 2x^2, 3x^2 and not 3x^3 so I am somehow confused.

EbenezerSon · 2014-09-01 23:57:01

My factorisation;
m^3 - 3m - m + 3 = 0

m^3 - 4m + 3= 0
m^3 - 3m - m + 3 =0
m( m^2 - 3) -(m -3) = 0
(m - 1)(m^2 - 3) =0
let 3^x = m
(3)^2 = 3
3^2x = 3^1, 2x =1/2, x = 0.5

m = 1
3^x = 1 = 0. x = 0

Is the answers correct? If not then please, show me the correct steps

(sorry for yesterday, I was called away)

bobbym · 2014-09-02 00:25:26

Hi;

First let us see if I have the problem right:

EbenezerSon · 2014-09-02 00:59:57

Yes, they are correct

bobbym · 2014-09-02 01:10:46

You have factored the cubic incorrectly.

EbenezerSon · 2014-09-02 01:16:17

In fact, I don't actually know how to factor a cubic equation

Math Is Fun Forum

#401 2014-08-30 04:13:39

Re: Simplify the following:

#402 2014-08-30 04:17:38

Re: Simplify the following:

#403 2014-08-30 04:26:36

Re: Simplify the following:

#404 2014-08-30 04:33:03

Re: Simplify the following:

#405 2014-08-30 20:44:32

Re: Simplify the following:

#406 2014-08-30 21:21:01

Re: Simplify the following:

#407 2014-09-01 01:00:39

Re: Simplify the following:

#408 2014-09-01 01:13:57

Re: Simplify the following:

#409 2014-09-01 01:21:37

Re: Simplify the following:

#410 2014-09-01 01:23:55

Re: Simplify the following:

#411 2014-09-01 01:33:12

Re: Simplify the following:

#412 2014-09-01 01:46:24

Re: Simplify the following:

#413 2014-09-01 01:52:43

Re: Simplify the following:

#414 2014-09-01 01:55:33

Re: Simplify the following:

#415 2014-09-01 02:04:55

Re: Simplify the following:

#416 2014-09-01 02:06:18

Re: Simplify the following:

#417 2014-09-01 02:09:12

Re: Simplify the following:

#418 2014-09-01 02:20:38

Re: Simplify the following:

#419 2014-09-01 02:31:02

Re: Simplify the following:

#420 2014-09-01 23:02:31

Re: Simplify the following:

#421 2014-09-01 23:57:01

Re: Simplify the following:

#422 2014-09-02 00:25:26

Re: Simplify the following:

#423 2014-09-02 00:59:57

Re: Simplify the following:

#424 2014-09-02 01:10:46

Re: Simplify the following:

#425 2014-09-02 01:16:17

Re: Simplify the following:

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