Polar form of a complex number will be
z = r(cos Īø + i sin Īø)
Rectangular form will be
z = x + iy
Convert the following polar form to rectangular form.
Problem 1 :
Solution :
= 4 [cos (7š/6) + i sin (7š/6)]
Here š lies in the third quadrant. Using ASTC, since it lies in the third quadrant, we use negative sign.
cos (7š/6) = cos (š + š/6) = -cos (š/6) = -ā3/2 |
sin (7š/6) = sin (š + š/6) = -sin (š/6) = -1/2
|
Applying the values in the respective places in the polar form, we get
Problem 2 :
Solution :
Here š lies in the first quadrant. Using ASTC, we have to use positive sign.
cos (š/6) = ā3/2 |
sin (š/6) = 1/2
|
applying the values in the respective places in the given polar form, we get
= 2ā7(ā3/2 + i(1/2))
= 2ā7(ā3 + 1i) / 2)
= ā7(ā3 + 1i)
Distributing ā7, we get
= (ā21 + iā7)
Problem 3 :
Solution :
Here š lies in the third quadrant. Using ASTC, we have to use negative sign for both.
cos (5š/4) = -1/ā2 |
sin (5š/4) = -1/ā2
|
Problem 4 :
Solution :
Applying the values in the respective places, we get
cos (š/2) = 0 |
sin (š/2) = 1 |
Problem 5 :
Solution :
Applying the values in the respective places, we get
cos (š/2) = 0 |
sin (š/2) = 1 |
Problem 6 :
Solution :
Here š lies in the third quadrant. Using ASTC, we have to use negative sign for both.
cos (4š/3) = -1/2 |
sin (4š/3) = -ā3/2 |
applying the values in the respective places in the given polar form, we get
= 2(-1/2 + i(-ā3/2))
= 2((-1 - iā3) / 2)
= (-1 - iā3)
Problem 7 :
Solution :
Here š lies in the first quadrant. Using ASTC, we have to use positive sign for both.
cos (š/6) = ā3/2 |
sin (š/6) = 1/2 |
applying the values in the respective places in the given polar form, we get
= 2(ā3/2 + i(1/2))
= 2((ā3 + i) / 2)
= ā3 + i
Problem 8 :
ā30(cos š + i sin š)
Solution :
cos š = -1 and sin š = 0
Applying these values in the respective places, we get
= ā30((-1) + i (0))
= -ā30
May 21, 24 08:51 PM
May 21, 24 08:51 AM
May 20, 24 10:45 PM