First Year Mathematics A (Differentiation & Linear Algebra) (1 Viewer)

matchalolz

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Re: MATH1131 help thread

Ok I think I understand what you're saying.

I barely remember anything from 3 unit, I was such a flop back then because I never thought I would be doing a uni math subject

Will try searching up general solutions
 

matchalolz

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Re: MATH1131 help thread

so theta = ± cos inverse (cosx)+ 2kπ

How do you know what value to use for k? so lost
 

matchalolz

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Re: MATH1131 help thread

I get what we're trying to do but I'm still not getting it, if I sub in like theta = 0 and x = Pi, then I get like l = -1/2 which makes no sense because l is meant to be an integer?
 

matchalolz

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Re: MATH1131 help thread

Screen Shot 2017-05-21 at 7.48.05 pm.png

This question is part of the chapter on Gaussian elimination and matrices etc.

Am I correct in thinking that this line would be parallel to the plane if its direction vector <2,3,-1> is a linear combination of <1,1,0> and <0,1,-1>? Or am I totally off? Someone please enlighten me
 

InteGrand

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Re: MATH1131 help thread

View attachment 33939

This question is part of the chapter on Gaussian elimination and matrices etc.

Am I correct in thinking that this line would be parallel to the plane if its direction vector <2,3,-1> is a linear combination of <1,1,0> and <0,1,-1>? Or am I totally off? Someone please enlighten me
That is correct.
 

InteGrand

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Re: MATH1131 help thread

You know how the line can be expressed as line = point + direction vector? Do I need to do anything with the point at all?
No, that point doesn't affect whether the line will be parallel to the plane.
 

matchalolz

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Re: MATH1131 help thread

Screen Shot 2017-05-27 at 10.38.43 am.png

Can someone please explain how you would integrate this integral by inspection? I know how to do it by substitution but the question specifically asks for that specific method.

I tried to differentiate (1+x^2)^3 but I got 6*x(1+x^2)^2 and i don't know what to do afterwards
 

matchalolz

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Re: MATH1131 help thread

View attachment 33946

Can someone please explain how you would integrate this integral by inspection? I know how to do it by substitution but the question specifically asks for that specific method.

I tried to differentiate (1+x^2)^3 but I got 6*x(1+x^2)^2 and i don't know what to do afterwards
 

InteGrand

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Re: MATH1131 help thread

View attachment 33946

Can someone please explain how you would integrate this integral by inspection? I know how to do it by substitution but the question specifically asks for that specific method.

I tried to differentiate (1+x^2)^3 but I got 6*x(1+x^2)^2 and i don't know what to do afterwards


 

matchalolz

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Re: MATH1131 help thread

The difference between "the substitution method" and inspection is that if you do it by inspection, you don't write out the substitution, you just write down the answer.
Ok thanks for the clarification

I'm probably just going to lose heaps of time in the exam coz I'm too dumb to do it in my head haha
 

leehuan

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Re: MATH1131 help thread

Ok thanks for the clarification

I'm probably just going to lose heaps of time in the exam coz I'm too dumb to do it in my head haha
You can always practice doing it the long way but very quickly (and because you're now at uni you can omit a few steps)
 

matchalolz

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Re: MATH1131 help thread

wtf is the point of the limit comparison test? I tried reading the theory but it's still not really sinking in

Does the numerator just become f(x) and the denominator become g(x) or do you have to actually figure out a function to compare it to??

Like where would you even start with these examples

Screen Shot 2017-05-29 at 11.24.01 am.png
 

InteGrand

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Re: MATH1131 help thread

wtf is the point of the limit comparison test? I tried reading the theory but it's still not really sinking in

Does the numerator just become f(x) and the denominator become g(x) or do you have to actually figure out a function to compare it to??

Like where would you even start with these examples

View attachment 33953
 

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