https://isaacphysics.org/questions/param_vol_rev_1?board=907569dd-74c5-47f2-9f6c-64066dafc922&stage=a_level

I managed to get the answer to part e, but I am unsure if I used the right method?

I calculated y=2+sqrt(x/2) to get the "upper part" of the quadratic curve and integrated this for a full rotation about the x-axis.

I then did my answer subtract the answer from part b (so 272pi/3 - 16pi/3=256pi/3 which turned out to be correct)

Is there a quicker way or did I use the correct method?

Help much appreciated

I managed to get the answer to part e, but I am unsure if I used the right method?

I calculated y=2+sqrt(x/2) to get the "upper part" of the quadratic curve and integrated this for a full rotation about the x-axis.

I then did my answer subtract the answer from part b (so 272pi/3 - 16pi/3=256pi/3 which turned out to be correct)

Is there a quicker way or did I use the correct method?

Help much appreciated

(edited 1 month ago)

Original post by mosaurlodon

https://isaacphysics.org/questions/param_vol_rev_1?board=907569dd-74c5-47f2-9f6c-64066dafc922&stage=a_level

I managed to get the answer to part e, but I am unsure if I used the right method?

I calculated y=2+sqrt(x/2) to get the "upper part" of the quadratic curve and integrated this for a full rotation about the x-axis.

I then did my answer subtract the answer from part b (so 272pi/3 - 16pi/3=256pi/3 which turned out to be correct)

Is there a quicker way or did I use the correct method?

Help much appreciated

I managed to get the answer to part e, but I am unsure if I used the right method?

I calculated y=2+sqrt(x/2) to get the "upper part" of the quadratic curve and integrated this for a full rotation about the x-axis.

I then did my answer subtract the answer from part b (so 272pi/3 - 16pi/3=256pi/3 which turned out to be correct)

Is there a quicker way or did I use the correct method?

Help much appreciated

Id guess they wanted you to do the volumes parametrically so

Int pi y(t)^2 dx/dt dt

over the appropriate limits for t. Gives the same result and its not hugely simpler, but its probably more direct.

Oh I see... thanks

how would you geometrically interpret the volume using Int pi y(t)^2 dx/dt dt, since the upper bound is -2 > the lower bound of 0, do you just think of it by swapping the upper and lower bounds and multiplying this volume by negative one, since

how would you geometrically interpret the volume using Int pi y(t)^2 dx/dt dt, since the upper bound is -2 > the lower bound of 0, do you just think of it by swapping the upper and lower bounds and multiplying this volume by negative one, since

Original post by mosaurlodon

Oh I see... thanks

how would you geometrically interpret the volume using Int pi y(t)^2 dx/dt dt, since the upper bound is -2 > the lower bound of 0, do you just think of it by swapping the upper and lower bounds and multiplying this volume by negative one, since

how would you geometrically interpret the volume using Int pi y(t)^2 dx/dt dt, since the upper bound is -2 > the lower bound of 0, do you just think of it by swapping the upper and lower bounds and multiplying this volume by negative one, since

Just use the limits 0 to -2. You could reverse them and negate the integral, but it ends up the same. You can always parametrically define it in terms of -t and it would make "more sense" for this curve segment, but reality is youre simply flipping the limits from x to t and the values are fairly irrrelevant as long as theyre correct.

(edited 1 month ago)

- MEI A Level Further Maths Core Pure 22nd May 2024
- Implicit and parametric curves
- Parametrics
- Edexcel Maths AEA 2023
- AQA paper 1 further maths
- Edexcel paper 2
- Parametric integration
- AQA further maths paper 1
- How to choose between Pearson and Spearman correlation?
- Maths parametric integration
- "My Cambridge Application" Help
- Parametric equations
- Cartesian Equations-finding arc length
- One cubic root is reciprocal of other question
- Parabola coordinates (FP1) maths help
- Edexcel A Level Mathematics Paper 2 (9MA0 02) - 13th June 2023 [Exam Chat]
- Architectural Apprenticeship Advice
- chemistry
- Please help
- Question on standard solutions

Last reply 1 week ago

Edexcel A Level Mathematics Paper 2 unofficial mark scheme correct me if wrongMaths

72

Last reply 1 week ago

Edexcel A Level Mathematics Paper 2 unofficial mark scheme correct me if wrongMaths

72