Express the given complex number in the form \(a + ib : (5i)(-\dfrac{3}{5i})\)
Solution and Explanation
\(a + ib : (5i)(-\dfrac{3}{5i})\)
\((5i)(- \dfrac{3}{5})=-5 ×(- \dfrac{3}{5}) × i × i\)
\(=-3i^2\)
\(=-3(-1)\)
[ As \(i^2=-1\)]
\(=3\)
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Concepts Used:
Complex Numbers and Quadratic Equations
Complex Number: Any number that is formed as a+ib is called a complex number. For example: 9+3i,7+8i are complex numbers. Here i = -1. With this we can say that i² = 1. So, for every equation which does not have a real solution we can use i = -1.
Quadratic equation: A polynomial that has two roots or is of the degree 2 is called a quadratic equation. The general form of a quadratic equation is y=ax²+bx+c. Here a≠0, b and c are the real numbers.
