C1 Indices question Watch

nazz06
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#1
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Hey,

An optional question from my homework was this ;

Express (16a^6)^-1/2 as an algebraic fraction in simplified form.

My method ;

1/(16a^6)^1/2

1/4a^3

I square rooted for the 16 but i didnt know what button to use as that.

anyway is that my final answer? Or did i do something wrong.

Also there was this question, which i was unsure on

Express 1/(4throotA)^5/3 in the form a^2 stating the value of n.

Any help is appreciated .

Thanks
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generalebriety
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#2
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1/(4a^3) is fine.

Notice that the 4th root of A is just A^(1/4), and use standard index rules from there. (I don't know what you mean by "in the form a^2, stating the value of n".)
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nazz06
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sorry, what i meant was in the form a^n , stating the value of N.

Thanks for the help
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nazz06
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Sorry for the double post,

But another section of my work sheet simply says,

'Find the factors of each of the following' :

the varies question from things like this 'x^2-9'

to (2x+1)^2 -x^2

for the first one i put as an answer (x+3)(x-3)

But i'm unsure as to whether or not this is right, I answered all the other questions in the same format.

Any assistance would be handy .
Thanks again
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someperson
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i think that's right =)
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generalebriety
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#6
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(Original post by nazz06)
sorry, what i meant was in the form a^n , stating the value of N.

Thanks for the help
Ah. Be careful with your capital letters; a, A, n, N are all different in maths, so I was getting confused that you had an A in your fraction and an a elsewhere. Anyway, like I said, use index rules on it for now.

(Original post by nazz06)
Sorry for the double post,

But another section of my work sheet simply says,

'Find the factors of each of the following' :

the varies question from things like this 'x^2-9'

to (2x+1)^2 -x^2

for the first one i put as an answer (x+3)(x-3)

But i'm unsure as to whether or not this is right, I answered all the other questions in the same format.

Any assistance would be handy .
Thanks again
Yeah, that's fine. (The question isn't very well worded, but it does just want you to split them up like that.)

Can you think of how to factorise (2x+1)^2 - x^2? (Hint: expand out the brackets, and try to factorise the resulting quadratic. You might need to solve it by another method first.)
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nazz06
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well for that question, i had this as an answer

(3x+1) (x+1).

When i expanded the brackets for the original question i had 4x^2 + 4x + 1. I subtracted x^2 like it also said in the question.
My final answer multiplies out to 3x^2 + 4x + 1.

Which i presume is right.

Thankk you
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generalebriety
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(Original post by nazz06)
well for that question, i had this as an answer

(3x+1) (x+1).

When i expanded the brackets for the original question i had 4x^2 + 4x + 1. I subtracted x^2 like it also said in the question.
My final answer multiplies out to 3x^2 + 4x + 1.

Which i presume is right.

Thankk you
But it's clearly not right, because it's not the expression in the question, is it?
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nazz06
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Your right, but i presumed it was right because the original expression has a -x^2 in it.
Where have i gone wrong??

Sorrry
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generalebriety
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(Original post by nazz06)
Your right, but i presumed it was right because the original expression has a -x^2 in it.
Where have i gone wrong??

Sorrry
Wait, sorry, I'm the one who's wrong here - I misread your solution slightly. It is right after all, but it could do with being written a bit more clearly.
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nazz06
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Don't apologise . Im just glad i solved it.

Thanks for the help
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boromir9111
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Okay, don't understand some of the posts, i believe they deviated away from the second, so just so i understand it asks,  \frac{1}{A^\frac{1}{4}}^(\frac{5  }{3})

okay, not the best way of showing it but you get the point, so isn't just simply that  n = -\frac{5}{12} ?????
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