1
IIT-JEE 1998
MCQ (More than One Correct Answer)
+2
-0.5
The value of the sum $$\,\,\sum\limits_{n = 1}^{13} {({i^n}} + {i^{n + 1}})$$ , where i = $$\sqrt { - 1} $$, equals
A
i
B
i - 1
C
- i
D
0
2
IIT-JEE 1987
MCQ (More than One Correct Answer)
+2
-0.5
If $${{{z_1}}}$$ and $${{{z_2}}}$$ are two nonzero complex numbers such that $$\left| {{z_1}\, + {z_2}} \right| = \left| {{z_1}} \right|\, + \left| {{z_2}} \right|\,$$, then Arg $${z_1}$$ - Arg $${z_2}$$ is equal to
A
$$ - \pi $$
B
$$ - {\pi \over 2}$$
C
0
D
$${\pi \over 2}$$
3
IIT-JEE 1987
MCQ (More than One Correct Answer)
+2
-0.5
The value of $$\sum\limits_{k = 1}^6 {(\sin {{2\pi k} \over 7}} - i\,\cos \,{{2\pi k} \over 7})$$ is
A
- 1
B
0
C
- i
D
i
4
IIT-JEE 1986
MCQ (More than One Correct Answer)
+2
-0.5
Let $${z_1}$$ and $${z_2}$$ be complex numbers such that $${z_1}$$ $$ \ne $$ $${z_2}$$ and $$\left| {{z_1}} \right| =\,\left| {{z_2}} \right|$$. If $${z_1}$$ has positive real and $${z_2}$$ has negative imaginary part, then $${{{z_1}\, + \,{z_2}} \over {{z_1}\, - \,{z_2}}}$$ may be
A
zero
B
real and positive
C
real and negative
D
purely imaginary
JEE Advanced Subjects
EXAM MAP
Joint Entrance Examination
JEE MainJEE AdvancedWB JEEBITSAT
Medical
NEET
Graduate Aptitude Test in Engineering
GATE CSEGATE ECEGATE EEGATE MEGATE CEGATE PIGATE IN