# C3 Maths help please [URGENT]Watch

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#1
Where do I even start with this question ? (C3 Solomon paper D)

Pic below:
Attachment 757334
0
#2
Question
0
1 year ago
#3
Not sure about the first but for the second I would do
ln x^2/e = lnx^2 - ln e
= lnx^2 - 1
= 2lnx - 1
= 2y - 1

I'm not sure if that's right tho you'll have to check x
1
1 year ago
#4
Here are some clues.

For part (i):
Let a = log2(x). Now consider what that actually means (i.e. turn it into a power).

For part (ii):
1
1 year ago
#5
y = ln(x), therefore x = e^y.

i) logbase(2)(x) = logbase(2)(e^y) = ylogbase(2)(e).

ii) ln(x^2/e) = ln(x^2) - ln(e) = 2y - 1.

Part ii gives a nicer answer.
1
1 year ago
#6
(Original post by LL2018)
Question
write x in terms of y
lnx=y
therefore
e^y=x

then it's just
i)
log2(e^y)
(y)log2(e)

the answer above me is right for q2
1
#7
Thanks all!
0
#8
(Original post by FluuidKarma)
write x in terms of y
lnx=y
therefore
e^y=x

then it's just
i)
log2(e^y)
(y)log2(e)

the answer above me is right for q2
I've worked out the first two parts but how would I go about solving the last part? (part b):
0
#9
(Original post by JoshMach65)
y = ln(x), therefore x = e^y.

i) logbase(2)(x) = logbase(2)(e^y) = ylogbase(2)(e).

ii) ln(x^2/e) = ln(x^2) - ln(e) = 2y - 1.

Part ii gives a nicer answer.
How can I solve part b?
Attachment 757366
0
1 year ago
#10
(Original post by LL2018)
I've worked out the first two parts but how would I go about solving the last part? (part b):
just sub in what you found in part i and ii into the new equation and it should just be basic algebra from there
0
#11
Here are some clues.

For part (i):
Let a = log2(x). Now consider what that actually means (i.e. turn it into a power).

For part (ii):
Could you help me with part b please? 0
#12
(Original post by FluuidKarma)
just sub in what you found in part i and ii into the new equation and it should just be basic algebra from there
This is the solomon answer which I have no idea how they derived: 0
1 year ago
#13
(Original post by LL2018)
This is the solomon answer which I have no idea how they derived: Solomon used C2 Log rules to get the answer for part a (changing the base)

using their method you will and up with 0
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