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Cool-Light

32 √2 = 2^a

Find the value of a, how?
I thought i'd do
root 2 x32 = root 64, root 64 = 8 = 2^a, therefore a = 3?

(edited 10 years ago)

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Reply 1

Mr M

Study Forum Helper

Original post by Cool-Light

32 √2 = 2^a

Find the value of a, how?
I thought i'd do
root 2 x32 = root 64, root 64 = 8 = 2^a, therefore a = 3?

Yuk!

When you take the 32 into the square root sign it no longer stays as 32.

An easier approach is to express root 2 as a power of 2 and 32 as a power of 2.

And it's indices.

Reply 2

Cool-Light

So Mr.M if I express 32 as a power of 2, that would mean 2^5 = 32
but I don't understand why I would need to express root 2 as a power of 2?

Reply 3

ChildishHambino

Original post by Cool-Light

So Mr.M if I express 32 as a power of 2, that would mean 2^5 = 32
but I don't understand why I would need to express root 2 as a power of 2?

well if you know that root2=2^(0.5), then use basic indice laws.

(edited 10 years ago)

Reply 4

Mr M

Study Forum Helper

Original post by Cool-Light

So Mr.M if I express 32 as a power of 2, that would mean 2^5 = 32
but I don't understand why I would need to express root 2 as a power of 2?

\sqrt 2 = 2^{\frac{1}{2}}

Reply 5

davros

Original post by ChildishHambino

well if you know that root2=2^(0.5) then you dont need to.

That is expressing root 2 as a power of 2 :smile:

Reply 6

Cool-Light

I'm confused :s-smilie:

Reply 7

Cool-Light

so 32 x root 2 = cannot = root 64
why

Reply 8

Cool-Light

nope, I can't work it out :s-smilie:

2^5x2^0.5 = 2^a?

sqrt2 = 2^(1/2)

32= 2^5

2^(1/2)*2^5 = 2^a

Reply 11

Cool-Light

on the brink of suicide, why the hell do I feel so stupid

4^5.5 = 2^a
help?

I can do 4^5, but how the hell do I 0.5^4, is that 2?

ok so 2048 = 2^a

2048/2 = 1024? = ^a

right, pardon my language... I'm sorry that i've failed to understand this, but I thank everyone who tried to help me

Reply 17

Cool-Light

I think someone needs to re-visit chapter 1 on core 1...

Reply 18

Mr M

Study Forum Helper

Original post by Cool-Light

I think someone needs to re-visit chapter 1 on core 1...

This won't make you feel any better but the rule you need is a GCSE Grade C skill.

a^m \times a^n = a^{m+n}

2^5 \times 2^{\frac{1}{2}}=2^{?}

Reply 19

Cool-Light

hmm well this is what I would of done
2^5x2^1/2 = 4^5/1+1/2 we need the same denominators so multiply 5/1 by 2, therefore giving 10/2+1/2 = 11/2

4^11/2 = 2, kill me I know its wrong, stupid me

(edited 10 years ago)

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