Mathematics: Post your doubts here!

[studyingrobot457]

Oct/Nov 2007
View attachment 62759
Help me differentiate plz!

easy
product rule
this means
-e^(-x)*sin(x)+e^(-x)*cos(x)=0

now solve the equation

 

[Holmes]

easy
product rule
this means
-e^(-x)*sin(x)+e^(-x)*cos(x)=0

now solve the equation

Thanks bro! studyingrobot457
It helped

 

[NerdyBirdy]

Anyone there to help me I’m kinda stuck in this ques that says
A curve has equation y=2x^2-2x
Find the set of values of x for which y >9
It’s from 9709/12/nov/dec/13

 

[Thought blocker]

2x^2 - 2x > 9
2x^2 - 2x - 9 > 0
Solve this. And suppose u got solme value a and b where b < a then ur final answer will be x > a and x < b

Anyone there to help me I’m kinda stuck in this ques that says
A curve has equation y=2x^2-2x
Find the set of values of x for which y >9
It’s from 9709/12/nov/dec/13

 

[Lisa Lunina]

Guys, plz help me on this

 

[MShaheerUddin]

Guys, plz help me on thisView attachment 62931

We have to find integral constant C here

 

[Lisa Lunina]

We have to find integral constant C here

What should i do then? I am really bad when it comes to integral

 

[MShaheerUddin]

Ive attached the solution see.. If it doesnt help then tell me

 

[Lisa Lunina]

Ive attached the solution see.. If it doesnt help then tell me

Ooohh.. I dont see it before haha. Thank you! It helped me a lot

 

[Lisa Lunina]

Guys! Plz help me! Im stuck again on integration problem. I cant answer any of the question below.

 

[Boby Max]

Please help me on functions. I forgotten all the basics.

 

[MShaheerUddin]

Guys! Plz help me! Im stuck again on integration problem. I cant answer any of the question below.View attachment 62936

Here you go lisa ☺️ see attachments

 

[Lisa Lunina]

Thank you! Now i understand most of integral

Here you go lisa ☺️ see attachments
View attachment 62942View attachment 62943[/QUOTE

 

[Hadi Murtaza]

Please help me on functions. I forgotten all the basics.View attachment 62938

still need help with that ?

 

[thestudyguy]

Can anyone please help me .
9709/12/O/N/17


Each year, the value of a certain rare stamp increases by 5% of its value at the beginning of the year. A collector bought the stamp for $10 000 at the beginning of 2005. Find its value at the beginning of 2015 correct to the nearest $100.

 

[Hadi Murtaza]

Can anyone please help me .
9709/12/O/N/17


Each year, the value of a certain rare stamp increases by 5% of its value at the beginning of the year. A collector bought the stamp for $10 000 at the beginning of 2005. Find its value at the beginning of 2015 correct to the nearest $100.

Very similar to compound interest.
F = P(1 + r/100)^n
Where
F = Final amount
P = Initial amount
r = increment
n = number of years

F = 10,000(1 + 5/100)^10
F = 10,000(1.05)^10
F = 10,000(1.6289)
[ F = $16,289 ≈ $16,300 ]

 

[thestudyguy]

Very similar to compound interest.
F = P(1 + r/100)^n
Where
F = Final amount
P = Initial amount
r = increment
n = number of years

F = 10,000(1 + 5/100)^10
F = 10,000(1.05)^10
F = 10,000(1.6289)
[ F = $16,289 ≈ $16,300 ]

its a sequence question so i dont think they will give marks for this
btw there is no compound interest in the AS syllabus for maths

 

[AAnsarii]

Assalamu alaikum wa rahmatullah.
I picked up math again after a long time.

Pure Mathematics 1, by Hugh Neill and Douglas Quadling, Chapter 1, Miscellaneous exercise 1, questions 4, 20 and 22.
4. A(7,2) and C(1,4) are two vertices of a square ABCD.
a. Equation of the diagonal BD.
b. Coordinates of B and D.

For part a., I know the product of two diagonals is -1, but I can't get it
Q 20 is similar, but a rhombus.

22. Two lines have equations y=m1x+c1 and y=m2x+c2, and m1m2= -1. Prove that the lines are perpendicular.
(PS for 22, I couldn't type the 1s and 2s in subscript, sorry.)

Jazakumullahu khayr

 

[Hadi Murtaza]

Assalamu alaikum wa rahmatullah.
I picked up math again after a long time.

Pure Mathematics 1, by Hugh Neill and Douglas Quadling, Chapter 1, Miscellaneous exercise 1, questions 4, 20 and 22.
4. A(7,2) and C(1,4) are two vertices of a square ABCD.
a. Equation of the diagonal BD.
b. Coordinates of B and D.

For part a., I know the product of two diagonals is -1, but I can't get it
Q 20 is similar, but a rhombus.

22. Two lines have equations y=m1x+c1 and y=m2x+c2, and m1m2= -1. Prove that the lines are perpendicular.
(PS for 22, I couldn't type the 1s and 2s in subscript, sorry.)

Jazakumullahu khayr

a)
m(AC) = (y₂ - y₁)/(x₂ - x₁)
m(AC) = (4 - 2)/(1 - 7)
m(AC) = 2/-6 = -1/3
Therefore m(BD) would be = - 1/(-1/3) = 3

The midpoints of both diagnols will be the same since they intersect.
Midpoint = (x₁ + x₂)/2 , (y₁ + y₂)/2
Midpoint = (7 + 1)/2 , (2 + 4)/2
Midpoint = (4 , 3)

Using point slope formula
y - y₁ = m(x - x₁)
y - 3 = 3(x - 4)
y - 3 = 3x - 12
[ y = 3x - 9 ]

b)
The distance from the midpoint to points B and D is the same as the distance from the midpoint to A and C.
d² = (x - 4)² + (y - 3)²
d² = (7 - 4)² + (2 - 3)²
d² = 9 + 1
d² = 10

10 = (x - 4)² + (y - 3)²
Substituting y = 3x - 9
10 = (x - 4)² +(3x - 9 - 3)²
10 = x² - 8x + 16 + 9x² - 72x + 144
10x² - 80x + 150 = 0
x² - 8x + 15 = 0
(x - 5)(x - 3) = 0
[ x = 5 , 3 ]

y = 3x - 9
y = 3(5) - 9 , 3(3) - 9
[ y = 6 , 0 ]

Hence B and D are (3 , 0) and (5 , 6)

 

[Jenessa182]

Hi could someone help me with this question:
Simplify the following
(n+1)!/n!