How do you divide 6−i7−2i?
1 Answer
Apr 8, 2016
Explanation:
To divide this fraction we require to rationalise the denominator.
We do this by multiplying numerator/denominator by the
complex conjugate of the denominator If
a ± bi is a complex number then
a ∓ bi is it's conjugate Note that the 'real part' remains unchanged , while the sign of the 'imaginary part' changes.
Also (a+ bi)(a - bi) =
a2−b2 a real number and
i2=(√−1)2=−1 Now the conjugate of 7 - 2i is 7 + 2i
multiplying numerator / denominator by (7 + 2i)
⇒(6−i)(7+2i)(7−2i)(7+2i)=42+5i+249+4=4453+553i