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# The function lnx Watch

1. Is this right?

e^2x+1 = 2
2x +1 = ln 2
x = 0.5 ln( 2- 1)

I though for the last step:

x = 0.5 (ln(2) -1)

with the one outside the ln brakets?
2. You are correct. The last step is x = 0.5 (ln(2)-1)
3. (Original post by CharlieBoardman)
You are correct. The last step is x = 0.5 (ln(2)-1)
Thats what is thought but the mark sheme says this

0.5 ln( 2- 1)
4. (Original post by nazgul60)
Thats what is thought but the mark sheme says this

0.5 ln( 2- 1)
That's wrong.
5. (Original post by nazgul60)
Thats what is thought but the mark sheme says this

0.5 ln( 2- 1)
It is wrong because that gives 0.5ln(1) = 0 and this can be easily disproved by substituting x=0 into the initial equation.
6. (Original post by Micky76)
It is wrong because that gives 0.5ln(1) = 0 and this can be easily disproved by substituting x=0 into the initial equation.
Thats what i thought but just needed to be confident. Thanks!
7. Am I just being stupid or isn't x=0 the answer?

8. or

9. (Original post by BabyMaths)

or

Is it not multiplied by e instead of the +1?
10. (Original post by BabyMaths)

that one
11. (Original post by BabyMaths)

or

12. (Original post by nazgul60)
that one
In that case as you thought.
13. (Original post by nazgul60)
Thats what is thought but the mark sheme says this

0.5 ln( 2- 1)
Sometimes mark schemes have mistakes in them. Don't worry - you are correct!
14. (Original post by nazgul60)
that one
Then you are right/mark scheme is wrong.

probably just a typing error by a clerk who doesn't know to be careful with these things.

Updated: June 12, 2012
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