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# FP3 Super Quick Log Question!

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1. I get that the rationalised the denominator but how does ln(1- (1-x etc etc = -ln(1+root1 etc etc

basically I don't understand the final line
2. (Original post by creativebuzz)

I get that the rationalised the denominator but how does ln(1- (1-x etc etc = -ln(1+root1 etc etc

basically I don't understand the final line

So

Now you have

And you know that

So
3. (Original post by Zacken)

So

Now you have

And you know that

So
Ah I see! Last question, would you mind spotting where I went wrong my working out

Attachment 523547523549

Attachment 523547523549523500
Attached Images

4. (Original post by creativebuzz)
Ah I see! Last question, would you mind spotting where I went wrong my working out
Have you posted the right picture? I genuinely have no clue what's going on.

You want to solve the system;

and , you decided to let . This gives you two equations in two variables:

and , you can now solve for and in terms of .
5. (Original post by Zacken)
Have you posted the right picture? I genuinely have no clue what's going on.

You want to solve the system;

and , you decided to let . This gives you two equations in two variables:

and , you can now solve for and in terms of .
Oops sorry ignore the first picture, the last two are the relevant ones!

(I was meant to send

x + 2y + z = 2

6x + y - 4x =16

6x + 12y + 6z = 12
6x + y - 4z = 16

11y + 10z = -4

and then the rest of my working out is in the last picture I sent you)
6. (Original post by creativebuzz)
Oops sorry ignore the first picture, the last two are the relevant ones!

(I was meant to send

x + 2y + z = 2

6x + y - 4x =16

6x + 12y + 6z = 12
6x + y - 4z = 16

11y + 10z = -4

and then the rest of my working out is in the last picture I sent you)
Why are you solving for lambda? Solve for x and z in terms of lambda.

I can't give a more detailed reply because I'm not home, sorry!
7. (Original post by Zacken)
Why are you solving for lambda? Solve for x and z in terms of lambda.

I can't give a more detailed reply because I'm not home, sorry!
Didn't I do that in the rest of my working out?

Also, quick question, how do you do find the mod arg form of modz = root3

I know that the mod is root3 but I can't seem to get the argument
8. (Original post by creativebuzz)
Didn't I do that in the rest of my working out?

Also, quick question, how do you do find the mod arg form of modz = root3

I know that the mod is root3 but I can't seem to get the argument
It says right on top. means argument. So the argument of is .
9. (Original post by Zacken)
It says right on top. means argument. So the argument of is .
o
m
g
10. (Original post by creativebuzz)
o
m
g
Perhaps taking a break and relaxing for a while is in order?
11. (Original post by Zacken)
Perhaps taking a break and relaxing for a while is in order?
Lol yup!

Do you know how I can draw the graph V = 0.5tsin8t?
12. (Original post by creativebuzz)
Lol yup!

Do you know how I can draw the graph V = 0.5tsin8t?
Well, starts at (0,0) - has roots at bascally every integer multiple of . The amplitude gets bigger and bigger but it always bounded between the lines , maxima and minima exactly where you would expect them. That should be enough to draw the graph.

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