help needed in maths p3

[nischal shrestha]

this question is frm 2003 oct of p3. i don't know how to find the max arg frm the fig. actually wat does it mean???

 

[nischal shrestha]

how to do the first question of this??

 

[fireman]

how to do the first question of this??

Ok when the power of X is ame in the denominator as well as in the numerator "A" comes. Here there is x3 in both denominator and numerator.keep in mind,this kinds of questions comes

 

[nischal shrestha]

i didn't get u????

 

[Amanina]

for ON03 q7,
to answer the part iii, you need to have a sketch on part ii first.
| z - u | = 2
| z - 1 - 2i | = 2 it means that you have to sketch a circle at center (1,2) with radius 2. then, make a tangent line from origin to the circle. the tangent line will pass through point around (-0.7,1) (this is just assumption). then you calculate the angle from the x-axis to the tangent line. just use the simple Pythagoras theorem to find the angle. that is the greatest value of argument z. if i'm not mistaken.


for q8,
since the power of x for numerator and denominator is the same, you have to do division first.

f(x) = (x3 - x - 2) / (x-1)(x2 + 1)

you divide it and then you will get 1 + [ (x2 - 2x - 1) / (x - 1)(x2 +1) ]

this shows that the value for A is 1.

then do partial fraction as usual.