Maths Urgent Help needed!!

[XPFMember]

Assalamoalaikum!!

plz help me out with these two questions...i have an exam tomorrow..!!

Q:1 june:2010 first variant paper 1
http://www.xtremepapers.net/CIE/Interna ... _qp_11.pdf

Q:2 Nov:2009 first variant paper 1
http://www.xtremepapers.net/CIE/Interna ... _qp_11.pdf

JazakAllah Khair!

 

[XPFMember]

anyone??

 

[hassam]

question 1 for 2010.....tan(pi-x)=-ve k

REASONING:
just remember the unit circle....angle x is acute as mentioned in the question pi rads is equal to 180 deg......so 180-x is an obtuse angle which is located in the second quadrant...and tan value of any angle in second quadrant is -ve....

tan(1/2 pi-x)...nothing fancy here...1/2 pi is 90 deg...use the property tan x=1/(tan(90-x)) so u get the answer 1/k
sin x....hmm....so how we do it.....well use the identity sin^2 x + cos^2 x = 1 and tan x = sin x/cos x.....well ho do we use it .....express cos x in terms of sin x and tan x.....and u get cos x = sin x / tan x ......substitute the square of this value for cos^2 x in the the first identity....play around a litlle bit and u ll get the anser ...hope that helps

 

[hassam]

for second 1 i dont know cos i havent formaly studied rads yet.....bt this video can help u.......http://www.youtube.com/watch?v=QmxMPPkZpME

 

[XPFMember]

question 1 for 2010.....tan(pi-x)=-ve k

REASONING:
just remember the unit circle....angle x is acute as mentioned in the question pi rads is equal to 180 deg......so 180-x is an obtuse angle which is located in the second quadrant...and tan value of any angle in second quadrant is -ve....

tan(1/2 pi-x)...nothing fancy here...1/2 pi is 90 deg...use the property tan x=1/(tan(90-x)) so u get the answer 1/k
sin x....hmm....so how we do it.....well use the identity sin^2 x + cos^2 x = 1 and tan x = sin x/cos x.....well ho do we use it .....express cos x in terms of sin x and tan x.....and u get cos x = sin x / tan x ......substitute the square of this value for cos^2 x in the the first identity....play around a litlle bit and u ll get the anser ...hope that helps

JazakAllah!!
well i got the first part but this one...i didnt understand :
tan(1/2 pi-x)...nothing fancy here...1/2 pi is 90 deg...use the property tan x=1/(tan(90-x)) so u get the answer 1/k


can u plz tell me from which chapter is it...may be i havent done that..
P.S. I havent done tan curves..only sine and cosine i have done..is it smthng related to the curve??

 

[ahmed t]

for june question 1
the last part just draw a right angled triangle and make the opposite k and the adjacent 1 and then find the hypotenus in terms of k
after that find oposite/hypotenuses which is equal to sin
for second part which is tan(pi/2-x) i did not get hassams reasoning

 

[hassam]

evaluate tan 30 and tan 60 using calculator....and u ll C 1 is the inverse of other.....ryt?
from this u can formulate a property....rememba' p1 book ex 10 b......we cn use properties to solve questions ...
property is tan(90-x)=1/tan x

 

[XPFMember]

btw under which topic do these questions come??

 

[MAVtKnmJ]

These properties are mostly based on Trigonometry / Trigonometric Functions

 

[XPFMember]

*bump*

Assalamoalaikum!!

need a solution to Q:2 nov 2009...the link given in my first post..plz i'm stuck in that!!

 

[MAVtKnmJ]

If I am not mistaken first draw a cosine curve with one cycle having an amplitude at 3. Then put in different prominent values of x (like pi / 6, pi / 3, pi /2) in the line equation to get corresponding values of y and plot it on the graph.

Note: For accuracy this has to be done on the graph paper and keep the range in mind for both the line and the curve.

 

[XPFMember]

If I am not mistaken first draw a cosine curve with one cycle having an amplitude at 3. Then put in different prominent values of x (like pi / 6, pi / 3, pi /2) in the line equation to get corresponding values of y and plot it on the graph.

Note: For accuracy this has to be done on the graph paper and keep the range in mind for both the line and the curve.

Assalamoalaikum!!

JazakAllah Khair!

btw..since we just need to sketch..so we need not do it on a graph paper..

well i think i got it..i'll try to sketck..if i'm able to do it..then it's good otherwise will disturb u again

 

[MAVtKnmJ]

In the actual exam this kind of question is instructed to be drawn on the sketch paper, you won't get the proper function/drawing any other way.
So it's best to start practicing from the beginning.

 

[XPFMember]

In the actual exam this kind of question is instructed to be drawn on the sketch paper, you won't get the proper function/drawing any other way.
So it's best to start practicing from the beginning.

do u mean graph paper by saying sketch paper?

 

[MAVtKnmJ]

Yeah, the one with the boxes

 

[radian]

SORRY!! I really dnt knw how to do it. :?