Maths D 22

[Snowysangel]

Oh and listen when do we use the quadratic function, and when differentiation, to find the turning point?

 

[mohdumar]

Oh like x1 y1 x2 y2 formula! Could u answer my relative velocity question btw... Why can't we multiply the direction vector by the speed to find the velocity vector...why do we need the unit vector to do that?

because direction can be shown using infinite numbr of vectors like 3i+4j , 6i+8j all show same direction, so if we multiply speed by the direction vector given which can be anything for a given angle, then we can get infinite number of velocity vectors for same speed and direction (WHICH IS ABSURD) so we use the unit vector

 

[Sarah Paul]

I gave 6. From tangent. I didn't realize the need to differentiate in during the exam, I differentiated it after the exam and realized it was 4.5 and I gave 6 which WILL be out of range, so 1 mark lost.

But then dont they see the diagram wen marking coz it dapends on how people draw the tangent ryt

 

[Saad Mughal]

But then dont they see the diagram wen marking coz it dapends on how people draw the tangent ryt

They see the tangent, it's for 1 mark.
They see the answer, it's for 1 mark.
No further checking.

 

[Sarah Paul]

They see the tangent, its for 1 mark.
They see the answer, its for 1 mark.
No further checking.

they mark according to the tangent drawn ryt?

 

[Saad Mughal]

they mark according to the tangent drawn ryt?

Not really. They have a specified range. Usually one more and one less than the EXACT value for the gradient (which is 4.5 in this paper). They mark the answer using it.

 

[Sarah Paul]

Really??? But my maths tutor said that they mark acccording to the diagram drawn *confused*

 

[Saad Mughal]

Really??? But my maths tutor said that they mark acccording to the diagram drawn *confused*

I thought so too but from what I know, it doesn't work that way because if the tangent is CORRECTLY drawn, you'll always get the gradient that is within the specified range.

 

[Saad Mughal]

Really??? But my maths tutor said that they mark acccording to the diagram drawn *confused*

What Gradient did you get waise?

 

[Sarah Paul]

What Gradient did you get waise?

I actually cant remember. I dont have a good memory power

 

[Saad Mughal]

I actually cant remember. I dont have a good memory power

Oh. Then don't worry, I'm sure you must have been within the range.

 

[Sarah Paul]

Oh. Then don't worry, I'm sure you must have been within the range.

hehe thankyou

 

[Muhammad Shamoeel]

http://www.olevels.tk/