Conics: (1 Viewer)

[Alkenes]

Does anyone have questions by topic for the topic "Conics" ?

thanks

 

[Alkenes]

What is d/dx (x/(x-3)^1/2

Do we take (x-3)^1/2 to the top and use product rule??

 

[Carrotsticks]

Use chain rule for the outside, then quotient rule for the inside.

Alternatively, you could use quotient rule directly, but with sqrt(x) and sqrt(x-3).

 

[Alkenes]

I was just going to post "dw guys, I got it" lol

Thanks anyway Carrot

 

[Alkenes]

For integration questions like x/(1+x^2)^1/2 .dx

Are we allowed to solve it without using u substitiuion in HSC?

 

[Carrotsticks]

For integration questions like x/(1+x^2)^1/2 .dx

Are we allowed to solve it without using u substitiuion in HSC?

Yep! So long as your final answer is correct, you will not lose any marks.

But if you make even the tiniest mistake, you get 0.

 

[Alkenes]

So for any integration questions, we can use any method unless stated...and we get marks right??

and when we get a form like this 1/a^2 - x^2 .dx, do we have to solve it using partial fractions or just use In (a+x/a-x) +C in exam?

Thanks

Yep! So long as your final answer is correct, you will not lose any marks.

But if you make even the tiniest mistake, you get 0.

 

[Alkenes]

And also, when deriving equation of chords for ellipses and hyperbolas, do we need to show how we derived the (sums and products formula) for finding the gradient?
BOS doesnt expect us to know any formula, but we have to learn that for 3 unit anyway....

2) questions like where we have to find area of rectangle /triangles within an ellipse, is it in the syllabus?

 

[Carrotsticks]

So for any integration questions, we can use any method unless stated...and we get marks right??

and when we get a form like this 1/a^2 - x^2 .dx, do we have to solve it using partial fractions or just use In (a+x/a-x) +C in exam?

Thanks

Best to just use partial fractions in this situation because most students will mindlessly use that formula without thought, whereas the integral of x/sqrt{1-x^2} etc requires understanding of the solution.

And also, when deriving equation of chords for ellipses and hyperbolas, do we need to show how we derived the (sums and products formula) for finding the gradient?
BOS doesnt expect us to know any formula, but we have to learn that for 3 unit anyway....

If you use the sums to product etc formula, you can use it without derivation. Just be sure to state that you're using it.

HOWEVER I doubt in the HSC there would be a question that uses it explicitly. If it requires the use of it, then there will be a part (i) saying "Prove XXXX" where XXX is the sum/product formula.

 

[Alkenes]

I know that is derived using partial fractions, are we allowed to use that form straight away?

Best to just use partial fractions in this situation because most students will mindlessly use that formula without thought, whereas the integral of x/sqrt{1-x^2} etc requires understanding of the solution.



If you use the sums to product etc formula, you can use it without derivation. Just be sure to state that you're using it.

HOWEVER I doubt in the HSC there would be a question that uses it explicitly. If it requires the use of it, then there will be a part (i) saying "Prove XXXX" where XXX is the sum/product formula.

 

[Carrotsticks]

I know that is derived using partial fractions, are we allowed to use that form straight away?

Most likely not. I wouldn't risk it.

 

[Alkenes]

Thanks mate

2) questions like where we have to find area of rectangle /triangles within an ellipse, is it in the syllabus?

Most likely not. I wouldn't risk it.

 

[Carrotsticks]

Thanks mate

2) questions like where we have to find area of rectangle /triangles within an ellipse, is it in the syllabus?

Yep!