Question

4) Express the following in the form of a+ib.
a, beRi-_-1. State the values of a and b
1) (1 +21)(-2+1) ii) (1+1)(1-1)
(2+1)
i(4+31)
(1-1)
IV) 73-1) (1+21)
3+21 3-2i
vi)
2-512+51
2+/-3
vii)(1+1
ix) (-15+2/4)+(1-9)+(2+3/42-37)
41 -31 +3
x) (2+31(2-31) xi)
37-41-2​

Answer 1

Step-by-step explanation:

1)

(1+2i)(-2+i)

= -2 + i - 4i + i²

= -2 - 3i - 1

= -3 - 3i

Here

a = -3 and b = -3

2)

(1+i)(1-1)-1i(4 + 3i)(2 +i)

= (1 + i)(0) - 1i(4 + 3i)(2 +i)

= 0 - 1i(4 + 3i)(2 + i)

= -1i(4 + 3i)(2 + i) = (3 - 4i)(2+ i)

= 6 + 3i - 8i - 4i²

= 6 - 5i + 4

= 10 - 5i

Here

a = 10 and b = -5

3)

(1i) (3+2i)(3-2i)

= (i)(3² - i²)

= i(9 + 1)

= 10i = 0 + 10i

Here

a = 0 and b = 10

4)

(3-1)(1+2i)

= 3 + 6i - 1 - 2i

= 2 + 4i

Here

a = 2 and b = 4

5)

21 V-3

= 21√3√-1

= (21√3)i ∵ √(-1) = i

= 0 + (21√3)i

Here

a = 0 and b = (21√3)

Do in the same way others