Question

find modulus ?
urgent reply me first

Answer 1

$( \sqrt{5} + i \sqrt{3} )( - 2 + i) \\ = - 2 \sqrt{5} + \sqrt{5} i - 2 \sqrt{3} i + {i}^{2} \sqrt{3} \\ = - 2 \sqrt{5} - \sqrt{3} + i( \sqrt{5} - 2 \sqrt{3} ) \\ = - (2 \sqrt{5} + \sqrt{3} ) + i( \sqrt{5} - 2 \sqrt{3)} \\ modulus = \sqrt{ { - (2 \sqrt{5} + \sqrt{3} ) }^{2} + {( \sqrt{5} - 2 \sqrt{3} )}^{2} }$
modulus=√(20+3+4√15+5+12-4√15)
=√(20+3+5+12)=√40=2√10