(i) If z=3+4i, then find modulus of z i.e., |z|.
(ii) If z=4+3i, then find modulus of z i.e., |z|.

Answer

To find the modulus of the complex numbers given in the question, we will follow these steps:

### Part (i): Finding the Modulus of \( z = 3 + 4i \)

1. **Identify the real and imaginary parts**:
- For the complex number \( z = 3 + 4i \), the real part \( a = 3 \) and the imaginary part \( b = 4 \).

2. **Use the modulus formula**:
- The modulus of a complex number \( z = a + bi \) is given by the formula:
\[ |z| = \sqrt{a^2 + b^2} \]

3. **Substitute the values into the formula**:
- Substituting \( a = 3 \) and \( b = 4 \):
\[ |z| = \sqrt{3^2 + 4^2} \]

4. **Calculate the squares**:
- Calculate \( 3^2 = 9 \) and \( 4^2 = 16 \).

5. **Add the squares**:
- Now add them:
\[ 9 + 16 = 25 \]

6. **Take the square root**:
- Finally, take the square root:
\[ |z| = \sqrt{25} = 5 \]

### Part (ii): Finding the Modulus of \( z = 4 + 3i \)

1. **Identify the real and imaginary parts**:
- For the complex number \( z = 4 + 3i \), the real part \( a = 4 \) and the imaginary part \( b = 3 \).

2. **Use the modulus formula**:
- The modulus of a complex number \( z = a + bi \) is given by the formula:
\[ |z| = \sqrt{a^2 + b^2} \]

3. **Substitute the values into the formula**:
- Substituting \( a = 4 \) and \( b = 3 \):
\[ |z| = \sqrt{4^2 + 3^2} \]

4. **Calculate the squares**:
- Calculate \( 4^2 = 16 \) and \( 3^2 = 9 \).

5. **Add the squares**:
- Now add them:
\[ 16 + 9 = 25 \]

6. **Take the square root**:
- Finally, take the square root:
\[ |z| = \sqrt{25} = 5 \]

### Final Answers:
- (i) The modulus of \( z = 3 + 4i \) is \( |z| = 5 \).
- (ii) The modulus of \( z = 4 + 3i \) is \( |z| = 5 \).