CLASS_11_MATHS_SOLUTIONS_NCERT

Class XI Chapter 5 – Complex Numbers and Quadratic Equations Maths
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r
2
4
r 4 2 Conventionally, r
0
2cos
3
cos
6
3
2
and 2sin 1
1
and sin
2
[As lies in the I quadrant]
3 i r cos
i r sin
2cos i 2sin 2cos isin
6 6 6 6
This is the required polar form.
Question 8:
Convert the given complex number in polar form: i
Solution 8:
i
Let
rcos
0 and rsin
1
On squaring and adding, we obtain
r
cos r sin 0 1
2 2 2 2 2 2
2 2 2
r
r
2
cos sin 1
1
r 1 1 Conventionally, r
0
cos
0 and sin
1
2
i r cos
i r sin
cos i sin
2 2
This is the required polar form.