Question

if (1+i) (2-i) = a+ib then a and b​

Answer 1

Step-by-step explanation:

$(1 + i) + (2 - i) = a + ib \\ \\ 1i - 2i = a + ib \\ \\ 1i = a + ib \\ \\ \: answer$

Answer 2

Given that ,

$\star \: \rm \: (1+i) (2-i) = a+ib$

On simplifying , we get

$\rm \mapsto 2 - i + 2i - {(i)}^{2} = a + ib \\ \\ \rm \mapsto2 + i - ( - 1) = a + ib \: \: \: \{ \because \: {(i)}^{2} = - 1\} \\ \\\rm \mapsto 3 + i = a + ib$

$\sf \therefore \underline{The \: value \: of \: a \: and \: b \: are \: 3 \: and \: 1}$

Remmember :

$\rm \mapsto i = \sqrt{ - 1} \\ \\ \rm \mapsto {(i)}^{2} = - 1$