Mathematics: Post your doubts here!

[RoOkaYya G]

How to solve trigonometrical equations within the range of -180<x<180? Is there a specific rule for it? For example, tan x = 45 and sin 2x = 2 sin x

solve the trig normally.
to make the answer in range...always add or subtract 360 from it.
if the angle is x there shld be 2 solutions...but if despite adding or subtracting 360..one answer doesnt fall in range...give both answers...BUT rewrite the real answer which is in range for example.... x =45 and x =190
but the quest range is 0<x<180
so x = 45 for 0<x<180 <---------WRITE LIKE THIS

 

[Thought blocker]

Any doubts left?

 

[RoOkaYya G]

Any doubts left?

waiting for tht no one sends doubt nw

 

[Thought blocker]

waiting for tht no one sends doubt nw

You want me to ask you a doubt?

 

[RoOkaYya G]

ask.

You want me to ask you a doubt?

ill help u as much as i can

 

[Thought blocker]

ask.

ill help u as much as i can

For now I have someone to solve it, I will ask tomorrow. I have piles of it.

 

[RoOkaYya G]

t

For now I have someone to solve it, I will ask tomorrow. I have piles of it.

omorrow? hmmm ok

 

[Wolfgangs]

I'm still confused about how to solve equations within the range of -180<x<180. Is there any specific forumula(e) to help me out? And can someone please solve any good example for me?

 

[RoOkaYya G]

I'm still confused about how to solve equations within the range of -180<x<180. Is there any specific forumula(e) to help me out? And can someone please solve any good example for me?

give link to questions u cant work out.

 

[Camille96]

Hello, anyone help me with this number. It's from june 2005p3. Actually, i've been able to prove but the (ii) part , not getting the answer. If you could help me out plus include the explanation, it'd be great. Exams are on friday, and i'm still struggling with vectors II.

 

[RoOkaYya G]

Hello, anyone help me with this number. It's from june 2005p3. Actually, i've been able to prove but the (ii) part , not getting the answer. If you could help me out plus include the explanation, it'd be great. Exams are on friday, and i'm still struggling with vectors II.

find normal (n hat) by doing cross product with the direction of line l and the directon vector A.

replace in the formula r. n hat = a . n hat

a can be the point in line equation (4,-2,2)

replace n u get the answer.

 

[RoOkaYya G]

P3 maths question 5 please
If link doesnt work the paper is 9709 may/June 2012 p32

https://files.cie.org.uk/tss/684256...10b/544653a8/file/21/54021/9709_s12_qp_32.pdf

Thanks in advance

i cant open XPC papers i dunno y :S maybe server prob. cannot open it :O
screen shot the quest.

 

[Wolfgangs]

http://papers.xtremepapers.com/CIE/...S Level/Mathematics (9709)/9709_w09_qp_22.pdf

How to solve question Q6? Is there any easy method (formula) to use?

 

[Edison Weeho]

http://papers.xtremepapers.com/CIE/...S Level/Mathematics (9709)/9709_s13_qp_31.pdf

Anyone , who can help me to solve ? I dont understand, 31/m/j/13 question 7) b)

 

[Thought blocker]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Mathematics (9709)/9709_s13_qp_31.pdf

Anyone , who can help me to solve ? I dont understand, 31/m/j/13 question 7) b)

Video solution :

 

[Emma23]

for least value of arg z means the smallest angle possible
ths means the tangent to the cricle must be such tht it makes the least possible angle
so u draw the tangent from starting point O to where it makes the least possible angle with the circle
u calculate modulus of z by assuming the tangent the hypotenus of a right angled triangle.
use pythagoras theorem or sin rule if u want.
the O will be the radius of the circle
the H will the moduls of z
use sin rule. its easier.

Thank you!

 

[Thought blocker]

Question 5

dy/dx = e^(2x + y) ----- x = 0, when y = 0

dy/dx = (e^2x)(e^y)

e^-y dy = e^2x dx

-e^-y = (1/2)e^2x + C

for x = 0 and y = 0 --- -1 = (1/2) + C
C = -3/2

-e^(-y) = (1/2)e^2x - 3/2 <<< answer

 

[Lily9605]

Question 9b, please help!

 

[Thought blocker]

Question 9b, please help!

 

[Nazree]

HELP!! 9709/32/M/J/2013 question 10(ii) someone please explain it to me!