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Help with rearranging formulae

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Graemermac

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Hello, looking for a bit of help with these...

ln (y + 5) = 3.1, solve for Y to three decimal places

4 (^x+1) = 6^0.5x, solve for x

I= Imax (1 -e^-30t/0.01), find t

any help would be greatly appreciated, thanks
 
I hope this helps.
[latex]x = ln(y)\\
y = e^x[/latex]
 
When is your homework due?:rolleyes:
 
homework

Soon enough that there's no time to read the textbook? :D

Well then, maybe you should spend less time on the web and more time reading your assignments!:(
 
Well then, maybe you should spend less time on the web and more time reading your assignments!:(

You missed the point that this isn't the original poster.

However, having been down the pub watching Australia-v-someone :D. I shall attempt to answer the original questions. Probably wrongly.:D

OK, first one,

ln (y + 5) = 3.1, solve for Y to three decimal places

Well, I think that is,
Take antilog of both sides (is that the right term?)

(y+5) = e^3.5
Y=e^3.5-5
Y=17+ a bit I think.

Second one,
Not a valid equation. I think?

Third one,
Don't do Maximums.:D

Mike.
 
Probably wrongly.:D

Hopefully so :D -- maybe that will teach someone a lesson :D Not me of course! As you pointed out, I am not the OP, but a random member who finds it mildly annoying that the whippersnappers these days are conscripting people on the interwebs to do their homework for them. :D

Michael
 
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a random member who finds it mildly annoying that the whippersnappers these days are conscripting people on the interwebs to do their homework for them. :D

I must say, this thread wasn't even dimly disguised as anything other than a piece of homework :rolleyes: hopefully Hero's advice will be enough for them to learn how to do their own homework rather than cheating :eek:
 
Well, one week after the original post the homework should have already been handed in. So, who's up to answering questions 2 and 3?

Mike.
 
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No thanks, I'm glad that the days of calculus homework are behind me now :D also, the second question seems to have incorrect notation. I assume it's meant to be "4^(x+1) = 6^0.5x, solve for x"
 
t=0.01(ln(I/Imax-1))/30

Did it in my head, so double check me.

2nd wasn't a valid expression.
 
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4^(x+1) = 6^0.5x, solve for x

(x+1)log4=.5xlog6
x+1/.5x = log6/log4
2 + 2/x = log2
x = 2(1/log2-2)

Might be wrong, been 20years since college.
 
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