# Talk

## Maths question

(21 Posts)
bkgirl Mon 07-Mar-16 17:23:05

Hiya son is confused and I am hopeless at maths.

If anyone would mind telling us....
The square root of x multiplied by the square root of x cubed?

Redroses11 Mon 07-Mar-16 17:29:02

x to the power of 4?

Redroses11 Mon 07-Mar-16 17:30:27

To me, it would read something like this

(x/x)*(x/x)cubed.

But, it is a LONG LONG time since I did maths!

Hopefully a more intelligent person shall be along shortly.

imelda3 Mon 07-Mar-16 17:32:29

We think it would be x to the power of 5 - when you are multiplying numbers "to the power of " you add up the to the power of numbers (when dividing you minus them). Think that's right!

imelda3 Mon 07-Mar-16 17:33:30

Actually ignore that - clearly wrong as that's not what you are asking....... Sorry!

PetraDelphiki Mon 07-Mar-16 17:34:29

I think it's x2... means to the power of

Square root of x is x^1/2
Square root of x^3 is x times x^1/2

So you have x times x^1/2 times x^1/2 which gives you x^2

Or you could go with root(x) times root(x^3) is the same as root(x times x^3) dames as root (x^4) which is x^2

Turbinaria Mon 07-Mar-16 17:34:52

Square root of x multiplied by square root of (x cubed) is:

X^1/2 . X^3/2 = X^4/2 = X^2 , so answer is x squared

Redroses11 Mon 07-Mar-16 17:35:17

I'm curious now!

contortionist Mon 07-Mar-16 17:35:30

(Plus or minus) X squared.
Root of a times root of b equals root of a times b

Redroses11 Mon 07-Mar-16 17:36:50

Ok, well, that has sufficiently confused me now!

GinandJag Mon 07-Mar-16 17:36:57

X^(1/2) * X^(3/2)

= X^(4/2)

= X^2, or X-squared

PreAdvent13610 Mon 07-Mar-16 17:37:43

Can you post a photo of the question please

SallyGardens Mon 07-Mar-16 17:38:22

When multiplying, you add the powers if the base number is the same so the sum would look like this, where ^ means "to the power of" and * means "multiply" (to avoid confusion between Xs).

X^0.5 * (X^3)^0.5

X^0.5 * X^3.5

X^4

SallyGardens Mon 07-Mar-16 17:39:39

Now I'm confused too - ignore what I what I said.

mineofuselessinformation Mon 07-Mar-16 17:40:17

Gin's right.

Turbinaria Mon 07-Mar-16 17:45:49

contortionist has the compete answer, noting that square root can be plus or minus.

Surely extra marks for your child if they submit that

bkgirl Mon 07-Mar-16 18:57:55

OMG I just came back after cooking dinner - what absolute stars you are!!! Thank you so much I will indeed post a photo as well but really, you are all amazing.

noblegiraffe Mon 07-Mar-16 19:03:30

Surely just x^2. Where does the plus or minus come from?

Bolognese Mon 07-Mar-16 21:37:35

Actually the question is ambiguous: The square root of x multiplied by the square root of x cubed?

It could be either:

a) [ X^(1/2) * X(1^2) ] ^3

or

b) X^(1/2) * [ X(1^2) ] ^3

a) is (+/-) x^3

and

b) is (+/-) x^2

Bolognese Mon 07-Mar-16 21:43:42

Or indeed option c) I posted to quick sorry

c) [ X^(1/2) * X^3(1^2) ]

With the answer then being

c) (+/-) x^2

Bolognese Mon 07-Mar-16 22:28:27

Actually given the wording in the op it could even be

d) { [ X * X^(1/2) ](1^2) } ^3 = (+/-) x^2.25

e) [ X * X(1^2)^3 ] ^(1/2) = (+/-) x^1.25

f) [ X * X^3(1^2) ] ^(1/2) = (+/-) x^1.25

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