Edexcel FP3 - 27th June, 2016

Okay, does it apply also to distance between planes, lines? I mean perpendicular d=shortest d?
June 2013, q8 first part the first method used in the mark scheme is really confusing, if someone can explain that, I will be really grateful!

The way I would do it, is construct a parallel plane with the same normal vector.

The minus the two planes.

The mark scheme just used the equation on page 10

https://qualifications.pearson.com/content/dam/pdf/A%20Level/Mathematics/2013/Specification%20and%20sample%20assessments/N38210A-GCE-Mathematical-Formulae-Statistical-Tables.pdf

Reply 681

Geraer100

2

Original post by somevirtualguy

Honestly I don't have anything in my notes on finding the distance between two planes or a line and a plane. You only need to concern yourself with the distance between a point and a plane/line.

Regarding the distances between two lines, you'll either be asked to find the distance between two parallel lines or two skew ones.

And yes the dot product must equal 0 because cos(90) is 0.

Try visualising a line and the origin, no matter how you draw it, the shortest distance between the line and the origin will always be perpendicular to the line.

Hope this has helped

Really thanks for this, my worst topic is Vector. Good luck for tomorrow everyone!

Reply 682

Geraer100

2

Original post by Armpits

The way I would do it, is construct a parallel plane with the same normal vector.

The minus the two planes.

The mark scheme just used the equation on page 10

https://qualifications.pearson.com/content/dam/pdf/A%20Level/Mathematics/2013/Specification%20and%20sample%20assessments/N38210A-GCE-Mathematical-Formulae-Statistical-Tables.pdf

Thanks!!Yes I did that question with that method as well, but I was just wondering what formula they used, now I see!! Good luck for tomorrow!

Reply 683

Major-fury

6

Original post by Hineshtailor

yeah you can lol but, you only find that out the question after, i also assumed that at first

ah okay thank you for that

Reply 684

Hineshtailor

2

Original post by Geraer100

Thanks!!Yes I did that question with that method as well, but I was just wondering what formula they used, now I see!! Good luck for tomorrow!

for distance between two planes isnt it just, a.nhat minus the other a.nhat???
when given the equation of the plane is r.n=a.n

Good luck fellas.

2015 Q6 - what is going on with the area in part d? What method have they used

https://3a14597dd5c7aa2363f0675717665774b02557b0.googledrive.com/host/0B1ZiqBksUHNYQWE5bVRTVE9BLW8/June%202015%20MS%20-%20FP3%20Edexcel.pdf

Reply 687

Geraer100

2

Original post by Hineshtailor

for distance between two planes isnt it just, a.nhat minus the other a.nhat???
when given the equation of the plane is r.n=a.n

That question was about the perpendicular distance between a point and the plane, and you could use the method you said or use the formula in the formula booklet. For the distance between two planes, I don't know how to find that