Question

Find the modulus.
5. 3 + 4i
6. −2 − i
7. 7
8. 4i

Answer 1

Modulus of : 3 + 4i = 5 , -2 -i =
`√(5 )` , 7 =7 and 4i = 4

Explanation:

Let A = x+iy be a complex number.

Here, modulus of A =
`\sqrt{x^(2) + y^(2) }`

So here Similarly,

Modulus of 3 + 4i =
`\sqrt{3^(2) + 4^(2) }` =
`√(9 + 16 )` =
`√(25 )` = 5

Modulus of -2 - i =
`\sqrt{(-2)^(2) + (-1)^(2) }` =
`√(4 + 1 )` =
`√(5 )`

Modulus of 7 + 0i =
`\sqrt{7^(2) + 0^(2) }` =
`√(49 )` = 7

Modulus of 0 + 4i =
`\sqrt{0^(2) + 4^(2) }` =
`√(16 )` = 4