Maths paper 2.. 2012!!

[shafayat]

dat typ of question is not dere for our level. if a question appears lyk dat, da formula will b given to use. it came in M/J 2011

thx n surely I will pray ..

 

[IGCSE O/L student]

thx n surely I will pray ..

ur welcum!

 

[svenas]

dat typ of question is not dere for our level. if a question appears lyk dat, da formula will b given to use. it came in M/J 2011

Thank u for taking ur time to answer me...but my problem in this question (M/J 2011) is that when they gave the formula and asked to find the sum of even numbers, they found for the first 4oo and then multiplied it by two, which I didn't understand so plz explain me this step

 

[IGCSE O/L student]

Thank u for taking ur time to answer me...but my problem in this question (M/J 2011) is that when they gave the formula and asked to find the sum of even numbers, they found for the first 4oo and then multiplied it by two, which I didn't understand so plz explain me this step

dats coz we wnt da sum of da first 400 even numbers.
2 is 1 multiplied by 2, ryt? 4 is 2 multiplied by 2, ryt? so da sum for the first 400 numbers multiplied by 2 givs da ans 4 da first 400 even numbers.

 

[svenas]

dats coz we wnt da sum of da first 400 even numbers.
2 is 1 multiplied by 2, ryt? 4 is 2 multiplied by 2, ryt? so da sum for the first 400 numbers multiplied by 2 givs da ans 4 da first 400 even numbers.

 

[IGCSE O/L student]

???

 

[svenas]

dats coz we wnt da sum of da first 400 even numbers.
2 is 1 multiplied by 2, ryt? 4 is 2 multiplied by 2, ryt? so da sum for the first 400 numbers multiplied by 2 givs da ans 4 da first 400 even numbers.

yeah I got u... U know that if I take A* this would be due to ur help really cauz u r solving all my doubts...
Anyway a question came up which asked me to find the obtuse angle ABC in (o/n 2011 p41 q6)...I used normally the sine rule and found the answer as 48.5 degrees, but what they did is that they subtract 180-48.5 and got 131.5 ....THIS REALLY MADE ME SAD cauz this is the first time this question I faced and I cant understand it at all so plz make it clear for me and thanks

 

[IGCSE O/L student]

yeah I got u... U know that if I take A* this would be due to ur help really cauz u r solving all my doubts...
Anyway a question came up which asked me to find the obtuse angle ABC in (o/n 2011 p41 q6)...I used normally the sine rule and found the answer as 48.5 degrees, but what they did is that they subtract 180-48.5 and got 131.5 ....THIS REALLY MADE ME SAD cauz this is the first time this question I faced and I cant understand it at all so plz make it clear for me and thanks

awww! dats swt of u. but will b due 2 ur efforts as well.
sin x=sin(180-x)
so, sin (48.5)=sin(180-48.5)
thus, da value of da obtuse angle is 131.5

 

[svenas]

awww! dats swt of u. but will b due 2 ur efforts as well.
sin x=sin(180-x)
so, sin (48.5)=sin(180-48.5)
thus, da value of da obtuse angle is 131.5

I didn't get u that much, I'm sorry , try to explain it to me again plz, cauz this is the first time I solve this type of question

 

[svenas]

awww! dats swt of u. but will b due 2 ur efforts as well.
sin x=sin(180-x)
so, sin (48.5)=sin(180-48.5)
thus, da value of da obtuse angle is 131.5

In addition, I also wants to know that the sine and cosine rules only give acute angles ryt???

 

[IGCSE O/L student]

I didn't get u that much, I'm sorry , try to explain it to me again plz, cauz this is the first time I solve this type of question

ur ans is 48.5, ryt?
in a sin curve, dere r two x values for each y value.
sin x=sin(180-x)
x=48.5. da value for sin 48.5 is 0.7489557208....
n da value for sin(180-48.5) is also 0.7489557208....
so da angle cn be either 48.5, or 180-48.5, which is 131.5.

 

[IGCSE O/L student]

In addition, I also wants to know that the sine and cosine rules only give acute angles ryt???

i'm i'm not sure abt dat, sry!

 

[svenas]

i'm i'm not sure abt dat, sry!

Thank u last one 'sine' I understood, but for sine is there also two answers like sine?

 

[IGCSE O/L student]

Thank u last one 'sine' I understood, but for sine is there also two answers like sine?

i dnt get u

 

[svenas]

i dnt get u

sry..
I mean is there 2 solutions for cosine like sine

 

[IGCSE O/L student]

sry..
I mean is there 2 solutions for cosine like sine

yes, but i dnt hv da formula now. i'm in schul ryt now. after goin home, i'll check n den tell u asap, k?

 

[svenas]

yes, but i dnt hv da formula now. i'm in schul ryt now. after goin home, i'll check n den tell u asap, k?

ok, I'll be waiting....Also u didn't tell me about how u didi in p2?

 

[IGCSE O/L student]

ok, I'll be waiting....Also u didn't tell me about how u didi in p2?

u mean math? oh, it went well. Alhamdulillah!

 

[IGCSE O/L student]

ok, I'll be waiting....Also u didn't tell me about how u didi in p2?

cos x= -cos(180-x)

 

[svenas]

cos x= -cos(180-x)

thank u, I came up with new question, it's in m/j 2010 p41 q7 part c, really hard one..plz reply as soon as possible thanks