Maths, Addmaths and Statistics: Post your doubts here!

[Minato112]

thankyou, now im going to do the second part of the question and il let you know if if get the right answer, for lower bound , all i have to do is subtract the perimtere by 0.5 right?

They are asking the lower bound of the perimeter... So u have to calculate the lower bound for all the sides and add them.

 

[zainabkhann]

Yea somewhat...

okey thats good to know, i was on the website that u sent me, studying other topics, and its quite good i must say, gives thorough explanation with examples and illustrations.

 

[zainabkhann]

They are asking the lower bound of the perimeter... So u have to calculate the lower bound for all the sides and add them.

Right so first subtract them with 0.5 and then add all of them together, usually i add first and then subtract with 0.5

 

[zainabkhann]

Right so first subtract them with 0.5 and then add all of them together, usually i add first and then subtract with 0.5

Its the wrong way, and now im going to remember this

 

[zainabkhann]

0.9m = 90 cm
Now to the nearest ten centimeters

10 cm/2 = 5 cm

So the upper bound is 90cm + 5 cm = 95 cm = 0.95 cm (Btw u sure the mark scheme says 9.5?)

Hey i would like to ask you as to why you divided the 10 by 2?

 

[zainabkhann]

They are asking the lower bound of the perimeter... So u have to calculate the lower bound for all the sides and add them.

Okey for the second part i got 2.80 for the lower bound of the perimeter

 

[Minato112]

Hey i would like to ask you as to why you divided the 10 by 2?

Well the technique for upper or lower bound is to take the rounding figure (here it is "nearest to ten centimetres") and divide it by 2

Then,
For Upper bound : U add the divided figure to the original value
and For Lower bound : U subtract the divided figure from the original value.

 

[Minato112]

Okey for the second part i got 2.80 for the lower bound of the perimeter

Yea the answer is right

 

[zainabkhann]

Yea the answer is right

thankyou for the informative explanation, could you please explain me the translation part from this link http://www.s-cool.co.uk/gcse/maths/transformations/revise-it/transformations I cant understand how we get the new vector values once we draw the new shape, it doesnt make sense.

 

[Minato112]

thankyou for the informative explanation, could you please explain me the translation part from this link http://www.s-cool.co.uk/gcse/maths/transformations/revise-it/transformations I cant understand how we get the new vector values once we draw the new shape, it doesnt make sense.

When we do translation, we have to consider how the points moved first, horizontally and second, vertically

When the points move to the right or up, the vector is positive
and when the points move to the left or down, the vector is negative

Now, lets take for example point c (5 , 4). It has to undergo a translation of (3 -2) (srry i cant write in vector form...)

So the point c move 3 units to the left and 2 units down. (Remember left -> +, down -> -)

Its the same for the other points.

 

[zainabkhann]

When we do translation, we have to consider how the points moved first, horizontally and second, vertically

When the points move to the right or up, the vector is positive
and when the points move to the left or down, the vector is negative

Now, lets take for example point c (5 , 4). It has to undergo a translation of (3 -2) (srry i cant write in vector form...)

So the point c move 3 units to the left and 2 units down. (Remember left -> +, down -> -)

Its the same for the other points.

How did you get (3,-2)

 

[Minato112]

Well it is said there that he'll do a translation with the translation vector (3 -2)

 

[zainabkhann]

Well it is said there that he'll do a translation with the translation vector (3 -2)

I am still very confused about this, ur doing a good job in explaining its just i havent really looked at this topic deeply, the topic seems straightforward though, could you use another example (ur own example) and then explain again. that might help,

 

[Minato112]

I am still very confused about this, ur doing a good job in explaining its just i havent really looked at this topic deeply, the topic seems straightforward though, could you use another example (ur own example) and then explain again. that might help,

Ok. First of all u have to understand the word translate. It means to shift an object or anything from one place and move it to another place, that is only the position of the object changes.

Well u understood till here? :

When we do translation, we have to consider how the points moved first, horizontally and second, vertically

When the points move to the right or up, the vector is positive
and when the points move to the left or down, the vector is negative

Well srry gtg now, will explain it 2morrow... srry for any inconvenience

 

[zainabkhann]

Ok. First of all u have to understand the word translate. It means to shift an object or anything from one place and move it to another place, that is only the position of the object changes.

Well u understood till here? :

Yes i have understood this

 

[zainabkhann]

Btw could you help me in this: f(x)=x^3-4. find f-1(x)

 

[zainabkhann]

Guys can someone tell me how you would solve this:
Factorise: 2x^2+3x-20 I can never factorise these kind of questions. I know it is an expansion, if someone has a good link to notes, please send me the link and explain. thanks

 

[Bilal Khan]

I dont have the marking scheme for this
may/june 2012, paper 1 question 11, Im getting c=-3 as the answer. Please let me know if this is correct

ur answer is right.

 

[Bilal Khan]

Btw could you help me in this: f(x)=x^3-4. find f-1(x)

f-1(x)=cube root of (y+4)

 

[Bilal Khan]

Guys can someone tell me how you would solve this:
Factorise: 2x^2+3x-20 I can never factorise these kind of questions. I know it is an expansion, if someone has a good link to notes, please send me the link and explain. thanks

u have to make factors.this is the answer.i solved it.