If P is a multiple of n , then the sum of Pth power of nth roots of unity is
p
n
0
None of these
If the complex numbers z1,z2 and z3 represent the vertices of an equilateral triangle such that | z1 | = | z2 | = | z3 | , then the sum of z1,z2 and z3 is
-1
1
2
The value of is
1/5
-1/5
1/10
-1/10
The complex numbers z1,z2 and z3 satisfying are the vertices of a triangle, which is
Of zero area
Equilateral
Right - angled isosceles
Obtuse - angled isosceles
a = 0 and b = 1
a = 1 and b = 0
a = 2 and b = -1
a = -1 and b = 2
If the amplitude of a complex number is π/2, then the number is
Purely imaginary
Purely real
Neither real nor imaginary
If we express in the form of x + iy, we get
cos 49θ - i sin 49θ
cos 23θ + i sin 23θ
cos 49θ + i sin 49θ
cos 21θ + i sin 21θ
The polar form of complex number 1 + i is
√2 (cos π/4 + i sin π/4 )
√2 (cos 2π/4 + i sin 2π/4
√2 (cos π/4 - i sin π/4 )
√3 (sin 2π/4 + i cos 2π/4)
Let z1 and z2 be two roots of the equation z2 + az + b = 0, z being complex number.Further,assume that the origin , z1 and z2 form an equilateral triangle.Then
a2 = b
a2 = 2b
a2 = 3b
a2 = 4b
The solution of the equation | z | - z = 1 + 2i is
2 - 3/2 i
3/2 + 2i
3/2 - 2i
-2 + 3/2 i
