z=x+iy,x,y∈Z
zzˉ3+zˉz3=350
To find: the area of the rectangle whose vertices are the roots
z=reiθ,zˉ=re−iθ
zˉ3=r3e−3iθ,z3=r3e3iθ
zzˉ3=r4e−2iθ,zˉz3=r4e2iθ
zzˉ3+zˉz3=r4(e2iθ+e−2iθ)=2r4cos2θ
2r4cos2θ=350 ⇒ r4cos2θ=175
r2=x2+y2
r2cos2θ=x2−y2
r4cos2θ=(x2+y2)(x2−y2)=175
x4−y4=175
(x2−y2)(x2+y2)=175
a=x2−y2,b=x2+y2
ab=175,b>a>0
x2=2a+b,y2=2b−a
175=1×175=5×35=7×25
(1,175): x2=2176=88 ✗
(5,35): x2=240=20 ✗
(7,25): x2=232=16 ✓
x2=16 ⇒ x=±4
y2=225−7=9 ⇒ y=±3
z=±4±3i
width=4−(−4)=8,height=3−(−3)=6
Area=8×6=48
Area=48⇒option (1)