Mathematics: Post your doubts here!

[nehaoscar]

S14-31
Pls explain part ii

 

[Konstantino Nikolas]

View attachment 59135
S14-31
Pls explain part ii

i was just going to post the reply to the integration question guess you got that right?

 

[Konstantino Nikolas]

View attachment 59135
S14-31
Pls explain part ii

If you take n= 32, n < 25 ... as n should be slightly > 32 for Tn to be equal to 25.
Hope you understand that.

 

[nehaoscar]

i was just going to post the reply to the integration question guess you got that right?

Yep got it! Sorry if you had done it cause of me!

 

[nehaoscar]

View attachment 59136

If you take n= 32, n < 25 ... as n should be slightly > 32 for Tn to be equal to 25.
Hope you understand that.

Ohh so we have to use the arithmetic series progression!? Oh gosh P3 has P1 stuff
I wasn't taking the plus 1 so I was getting 31
Thanksss a lot!!

 

[Konstantino Nikolas]

Yep got it! Sorry if you had done it cause of me!

that was simple ... lol np ... practice for me

Ohh so we have to use the arithmetic series progression!? Oh gosh P3 has P1 stuff
I wasn't taking the plus 1 so I was getting 31
Thanksss a lot!!

Yeah. I too realised that only while doing this question. :/
anytime

 

[nehaoscar]

How to do part iii please??? :O
S14-32

 

[Maayee]

Can anyone help me with this
the last part...a=1.82ms^-2 and T=49.1N

 

[Konstantino Nikolas]

Can anyone help me with this
the last part...a=1.82ms^-2 and T=49.1N

 

[nehaoscar]

 

[Konstantino Nikolas]

View attachment 59139
How to do part iii please??? :O
S14-32

 

[Konstantino Nikolas]

View attachment 59146

 

[Maayee]

View attachment 59145

Thank u soooo much

 

[Konstantino Nikolas]

Thank u soooo much

no problem at all

 

[Maayee]

and can u help me with this too...
Q8 part iv)...the ans is 259N
and Q9 part iii and iv.... the answers are for iii) T=30,8.87 and for iv) its 1.23kg
plsss...

 

[nehaoscar]

To find the normal, how did you get the (0,1,0)?
Also multiplying BC into the j i.e (1,1,-4) * (0,1,0) wouldn't it give (0,1,0) ... how does it give (4,0,1)?

 

[nehaoscar]

Thankyouuu!

 

[holoholo]

Can someone please show me how to do question (ii) ?

 

[nehaoscar]

View attachment 59149
Can someone please show me how to do question (ii) ?

We want the distance of green line
Use sine rule
[3/sin(pi/2)]*(sin(pi/4))
= 3/2 *root2

 

[Konstantino Nikolas]

To find the normal, how did you get the (0,1,0)?
Also multiplying BC into the j i.e (1,1,-4) * (0,1,0) wouldn't it give (0,1,0) ... how does it give (4,0,1)?

Lol ... this is vector multiplication, you can't just multiply like that normally. And the result is a cross product of two vectors ... I'll just post a pic of how to do it.

Don't mind the pencil mapping thing ... i tried visually doing the multiplication ... looks like a mess.

And yes, I'm doing that coz the cross product of two vectors gives you a 3rd vector that is perpendicular to both the original 2 vectors you are multiplying.

So in your question, if the vector is perpendicular to both j and BC, then it is also perpendicular to the plane. I've taken j since we have not been given any other information sufficient to solve the problem. So we get n and voila! You have your eqn of the plane. B|