Maths, Addmaths and Statistics: Post your doubts here!

[Saad Mughal]

how m not getting it

Oh sorry, I stand corrected; I made a mistake of adding 10% to the sales price. Its fixed. 10% commission if he sells 10 or more, 25% commission if he sells 50 or more.

 

[Suchal Riaz]

Have you solved the chapter from classified?

ya

 

[Suchal Riaz]

sorry but I thought you were talking about maths,I dont take addmaths so I guess I cant guide you here

i judged that from ur reply. sorry for disturbing u.

 

[Saad Mughal]

ya

Then you must know that in evety question we get a perfect fit (or near perfect) so that question is one out of the bloom I guess.

 

[Khadija_1234]

please help with these questions

 

[Saad Mughal]

please help with these questions

PQ = 7 cm , MN = 14 cm
Let A and B be midpoints of MN and PQ respectively.
Therefore AB = 3 cm (given), PB=BQ=3.5 cm, MA=AN=7cm
Now,
Considering Triangle OAN,
Let OA=x, ON=r,
Using Pythagoras Theorem,
(ON)^2=(OA)^2+(AN)^2
(r)^2=(x)^2+(7)^2
(r)^2=(x)^2+49...... (i)

Considering Triangle OBQ,
OB=x+3, OQ=r (same radius as ON)
Using Pythagoras Theorem,
(OQ)^2=(OB)^2+(BQ)^2
(r)^2=(x+3)^2+(3,5)^2....... (ii)

Solving Simultaneously,
(x)^2+49=(x)^2+6x+9+12.25
6x=27.75
x=4.625 cm

From (i),
(r)^2=(4.625)^2+49
(r)^2=70.39
r=8.39 cm (3 sig. fig.)

See diagram for better understanding.

 

[Saad Mughal]

please help with these questions

XY= 16 cm, NP = 2 cm, OP=OX=OY (radii)
Let ON=x, OY=r,
XN=NY=8 cm (Midpoint),
OP=ON+NP
OP=x+2
Therefore,
OY=x+2
r=x+2.... (i)

Considering Triangle ONY,
Using Pythagoras Theorem,
(r)^2=(x)^2+(8)^2(r)^2=(x)^2+64.... (ii)

Solving Simultaneously,
(x+2)^2=(x)^2+64
x^2+4x+4=x^2+64
4x=60
x=15 cm

Therefore,
r=15+2
r=17 cm

Hope that helps.

 

[Haris Bin Zahid]

Look at these two transformations:
1. Stretch with y-axis as invariant line and stretch factor of -1.
2. Reflection in the y-axis.
Aren't 1 and 2 the same?

 

[Saad Mughal]

Look at these two transformations:
1. Stretch with y-axis as invariant line and stretch factor of -1.
2. Reflection in the y-axis.
Aren't 1 and 2 the same?

Yes, they are the same since they both have the same transformation matrices.

 

[asma tareen]

PQ = 7 cm , MN = 14 cm
Let A and B be midpoints of MN and PQ respectively.
Therefore AB = 3 cm (given), PB=BQ=3.5 cm, MA=AN=7cm
Now,
Considering Triangle OAN,
Let OA=x, ON=r,
Using Pythagoras Theorem,
(ON)^2=(OA)^2+(AN)^2
(r)^2=(x)^2+(7)^2
(r)^2=(x)^2+49...... (i)

Considering Triangle OBQ,
OB=x+3, OQ=r (same radius as ON)
Using Pythagoras Theorem,
(OQ)^2=(OB)^2+(BQ)^2
(r)^2=(x+3)^2+(3,5)^2....... (ii)

Solving Simultaneously,
(x)^2+49=(x)^2+6x+9+12.25
6x=27.75
x=4.625 cm

From (i),
(r)^2=(4.625)^2+49
(r)^2=70.39
r=8.39 cm (3 sig. fig.)

See diagram for better understanding.

View attachment 23460

yay i had tried this yesterday and its correct

 

[Haris Bin Zahid]

Yes, they are the same since they both have the same transformation matrices.

Then how do we answer Q11(a-iv) ? Why not in terms of stretch?

 

[Saad Mughal]

You can write both but you MUST describe them correctly, i.e. Reflection with line of reflection y=x OR A stretch with y-axis invariant line and stretch factor -1.

 

[Khadija_1234]

PQ = 7 cm , MN = 14 cm
Let A and B be midpoints of MN and PQ respectively.
Therefore AB = 3 cm (given), PB=BQ=3.5 cm, MA=AN=7cm
Now,
Considering Triangle OAN,
Let OA=x, ON=r,
Using Pythagoras Theorem,
(ON)^2=(OA)^2+(AN)^2
(r)^2=(x)^2+(7)^2
(r)^2=(x)^2+49...... (i)

Considering Triangle OBQ,
OB=x+3, OQ=r (same radius as ON)
Using Pythagoras Theorem,
(OQ)^2=(OB)^2+(BQ)^2
(r)^2=(x+3)^2+(3,5)^2....... (ii)

Solving Simultaneously,
(x)^2+49=(x)^2+6x+9+12.25
6x=27.75
x=4.625 cm

From (i),
(r)^2=(4.625)^2+4
(r)^2=70.39
r=8.39 cm (3 sig. fig.)

See diagram for better understanding.

Thanks

 

[Saad Mughal]

 

[Khadija_1234]

You explain really well
I get it now

 

[Saad Mughal]

Oh. Thanks!

 

[Suchal Riaz]

i always thought that integration by parts, u-substitution and trig substitution are not in syllabus as they are not in book but i recently saw a question which has to be done by u-substitution. so does it mean that others are also included(by parts and trig substitution)

 

[Saad Mughal]

i always thought that integration by parts, u-substitution and trig substitution are not in syllabus as they are not in book but i recently saw a question which has to be done by u-substitution. so does it mean that others are also included(by parts and trig substitution)

Yeah, our book doesn't have them either. Our teacher solved questions and helped us with these topics.

 

[Suchal Riaz]

Yeah, our book doesn't have them either. Our teacher solved questions and helped us with these topics.

even trig substitution?

 

[Saad Mughal]

Trigonometric Substitution is hard. I've only done I guess a couple of questions but they won't be a part of the exams surely!