URGENT HELP REARRANGING! Final due monday!!!

[nastya0987]

how do I rearrange to find a!!!! where e = euler's number

73/410 = ae^(-2a)

i need to do this for a variety of different equations with different x values (-2 in this one) and probabilities (73/410).

[jakesilove]

how do I rearrange to find a!!!! where e = euler's number

73/410 = ae^(-2a)

i need to do this for a variety of different equations with different x values (-2 in this one) and probabilities (73/410).

Hey! I honestly can't find a way of explicitly getting an answer out using normal methods; I feel like you can't. The way I would have attempted to attack the question is like this





Wolfram alpha seems to suggest there isn't a straight answer, so I don't think there's much more we can do here using conventional methods. If you wanted to be smart, you could guess an answer that's close using your calculator, and then use Newton's method? There also happen to be two answers in this particular case.

[jakesilove]

Hey! I honestly can't find a way of explicitly getting an answer out using normal methods; I feel like you can't. The way I would have attempted to attack the question is like this





Wolfram alpha seems to suggest there isn't a straight answer, so I don't think there's much more we can do here using conventional methods. If you wanted to be smart, you could guess an answer that's close using your calculator, and then use Newton's method? There also happen to be two answers in this particular case.

For instance, a=1 is actually pretty damn close (as is a=0). So, we could use either of those as our initial approximation. However, are about 0.38 and 0.64, so the one you chose may affect the answer you end up getting.

[RuiAce]

how do I rearrange to find a!!!! where e = euler's number

73/410 = ae^(-2a)

i need to do this for a variety of different equations with different x values (-2 in this one) and probabilities (73/410).

Verifying what Jake said.

This is physically IMPOSSIBLE with elementary algebraic methods. The best you can get is to isolate a onto one side. You should post the entire question and not just this part so we can determine if there was a potential typo.

Methods of approximation are taught in the Ext 1 course.

[Shadowxo]

Normally for a question like this, you'd use a calculator and solve for a - you can't solve this by hand but you can plug it into a calculator that'll solve it for you, I'd expect that's what they want you to do.

[RuiAce]

Normally for a question like this, you'd use a calculator and solve for a - you can't solve this by hand but you can plug it into a calculator that'll solve it for you, I'd expect that's what they want you to do.

Guess and check might take a bit long for that one. They teach Newton's method in Ext 1 though.

[Shadowxo]

Guess and check might take a bit long for that one. They teach Newton's method in Ext 1 though.

Ah okay,
Last year we had a graphics calculator and we could just say solve(x=ab...,x) and it would give us solution for the x value, instead of having to use guess and check. I'm not sure if HSC has the same thing though

[RuiAce]

Ah okay,
Last year we had a graphics calculator and we could just say solve(x=ab...,x) and it would give us solution for the x value, instead of having to use guess and check. I'm not sure if HSC has the same thing though

Yeah I'm aware of that. No graphics calculators allowed in the HSC though.

List of approved calculators