let the two forces be F1 and F2

so root(F1^2+F2^2+2F1F2cos@)=R.............................(1)

where @ is the angle b/w the two forces....

now u see resultant will be maximum when @=0 ( because cos0=1)

and resultant will be minimum when @=180 (because cos180=-1)

hence according to ur question from (1)

root(F1^2+F2^2+2F1F2cos0)=35KN

=> F1+F2=35........................(2)

and similarly F1-F2=5...........(3)....

u will get F1 and F2.....

and when resultant is 5KN then the angle b/w them will be 180 (coz 5KN is the least one)

hope i helped u 

 slope of x axis(m1)=-{1/slope of y axis(m2)}

 put x+y=v

differentiate it wrt x

we get 1+dy/dx=dv/dx

now put it in ur question u will get 

dv/dx-1=(v+1)/v

dv/dx=(v+1)/v+1

now i think u can easily solve it

hope i helped u

2pie......

 see the angle bisector is the locus of a point which moves such that

it is always equidistant from the two given lines.....

let the point be P(h,k)

first making the c1 and c2(constant in given lines) of same sign

so eqn of angle bisector is 

|(a1h+b1k+c1)/{root(a12+b1^2+)}| = +_ |(a2h+b2k+c2)/{root(a2^2+b2^2)}|...............(1)

now evaluate a1a2+b1b2(of changed eqn after making c1 and c22 of same sign)...........(2) 

and also find (a1@+b1$+c1)(a2@+b2$+c2) .....................(3)

where (@,$)=(0,0) {origin}

if (a1@+b1$+c1)(a2@+b2$+c2)>0 then angle bisector with +ve sign(from 1 ) will contain the

point(origin in this case)

and if (a1@+b1$+c1)(a2@+b2$+c2)<0 then angle bisector with -ve sign(from 1) will contain the

point(origin).

now  find a1a2+b1b2

if  a1a2+b1b2>0 then  angle bisector with positive sign will be obtuse angle bisector.

if a1a2+b1b2<0 then ....................".......... with -ve sign.........".........acute angle

bisector.

now to find whether acute angle bisector  or obtuse angle bisector will contain the point

proceed like this

1)eqn 3 is +ve and eqn 2 is also +ve then obtuse angle bisector will contain the point(i.e. origin)

2)eqn 3 is +ve and eqn 2 is -ve then acute angle bisector will contain the point.

3)eqn3 is -ve and 2 is +ve then acute..........."..........................................

4)if 3 is -ve and 2 is -ve then obtuse ..................................."..........................