Mathematics: Post your doubts here!

[daredevil]

I'm not getting the correct answer for question 1 ... although I used the exact method as given in the ms....
It's pretty simple reallyy... only if someone cud show the calculations bcz maybeI'm making an error there....

thankss...

 

[Suchal Riaz]

I'm not getting the correct answer for question 1 ... although I used the exact method as given in the ms....
It's pretty simple reallyy... only if someone cud show the calculations bcz maybeI'm making an error there....

thankss...

I had my calculator on gra so my D was wrong. Then i switched to deg and answer was right. That might be the case with you.

 

[sitooon]

Solve the inequality I x I < I 5 + 2x I
I got two values to x as -5 and -5/3 and they are right ,
but how to make the inequalities finally

 

[yousef]

 

[Suchal Riaz]

Solve the inequality I x I < I 5 + 2x I
I got two values to x as -5 and -5/3 and they are right ,
but how to make the inequalities finally

X<-5 and x>-5/3 if ur answer was right.
I just made a rough sketch to identify the region(s) required.

 

[daredevil]

View attachment 37509
I had my calculator on gra so my D was wrong. Then i switched to deg and answer was right. That might be the case with you.

oohh yeahh u were rigghhtt!! thanks a lot!!

 

[yousef]

 

[Suchal Riaz]

oohh yeahh u were rigghhtt!! thanks a lot!!

Look at my dp

 

[syed1995]

Suchal Riaz
syed1995
Sorry for arguing , i had a very silly mistake !
I got the right ans with both!

haha no worries.. it's impossible to get a different answer cuz only the bases change nothing else.. and yea remember that antilog is e^x in ln instead of 10^x in lg that's the only change.

 

[midha.ch]

The random variable X has the distribution B (12, 0.2) .

a) Calculate P( X ≤ 1 )

b) Find the smallest value of x such that P ( X ≤ x) > 0.7

Can anyone solve part b ?? I need help asap

 

[ShreeyaBeatz]

I would like to know the answer to this as well.. How many marks is it worth and which year/paper mate?

Hello mate
The exact question(7) of this O/N 2005 was:
" 2x^3 + x^2 + 25 = 0 has one real root and two complex roots. verify that 1+2i is one of the complex roots"
yes, I know how to verify. But instead if the question was asked "what are the complex and real roots of this equation?" Then, what should I do?

Have a great year of the horses. Shine with love and loyalty in life

X and Y are related by x^n y = c
When we form equation it should be : nlogx +logy = logc

But in marking scheme they use (( ln )) instead of log ! how comes ?

You can write anything! This is because it is not specified in the question if it is base-e , or base 10

 

[syed1995]

Hello mate
The exact question(7) of this O/N 2005 was:
" 2x^3 + x^2 + 25 = 0 has one real root and two complex roots. verify that 1+2i is one of the complex roots"
yes, I know how to verify. But instead if the question was asked "what are the complex and real roots of this equation?" Then, what should I do?

Have a great year of the horses. Shine with love and loyalty in life


You can write anything! This is because it is not specified in the question if it is base-e , or base 10

Ah gotcha.. So the question you asked was off-topic.. *relief* Well I'll look it up for ya and answer you tomorrow of day after tomorrow..

Cheers

 

[sentry]

hi guys I need help... how can i get above (45/50 in S1 & M1) and (65/75 in P1 and P3) when practicing past papers... cause so far when I practice past papers I'm only getting (20/50 in S1), (35/50 in M1), (55/75 in P1) and (42/75 in P3)...please guys I need help

 

[Igcse stuff]

Hey guys, can someone assist me with good P3 notes on the topics Complex number, Differentiation, Integration and Vectors....I'm really in need of the notes

 

[Lyfroker]

http://papers.xtremepapers.com/CIE/...S Level/Mathematics (9709)/9709_s10_qp_11.pdf

Please explain q#5(ii)

 

[midha.ch]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Mathematics (9709)/9709_s10_qp_11.pdf

Please explain q#5(ii)

f(x) = 2 – 5(cosx)^2

maximum value of cosx = 1

since it is squared in the equation, cosx = -1 will give the same value for f(x) as cosx = 1

for max value of f(x), 5(cosx)^2 should be 0

therefore max f(x) = 2

for min value of f(x), cosx = 1 or cosx= -1

thus, minimum f(x) = -3

 

[daredevil]

Look at my dp

hahha shelly gotcha

 

[A star]

Hello mate
The exact question(7) of this O/N 2005 was:
" 2x^3 + x^2 + 25 = 0 has one real root and two complex roots. verify that 1+2i is one of the complex roots"
yes, I know how to verify. But instead if the question was asked "what are the complex and real roots of this equation?" Then, what should I do?

Have a great year of the horses. Shine with love and loyalty in life


You can write anything! This is because it is not specified in the question if it is base-e , or base 10

can you explain the process o verification please

 

[syed1995]

can you explain the process o verification please

Aap explain bohat acha kartay hain boii!

 

[abruzzi]

Could someone please help me with part (iii) of the question? Its kinda urgent
The answer to part(ii) is √20sin(theta + 63.43)
Thanks