Question

modulus of 12-5i is
a)13
b)12
c)-5
d)5​

Answer 1

$\underline{\underline{\purple{\textbf{Step - By - Step - Explanation : -}}}}$

Solution :

$\longrightarrow \rm |12 - 5i|$

$= \rm \sqrt{(12 ){}^{2} + (5) {}^{2} \times (i) {}^{2} }$

we know that,

• i² = -1

$= \rm \sqrt{12 {}^{2} + ( - 5) {}^{2} }$

$= \rm \sqrt{144 + 25}$

$= \rm \sqrt{169}$

$= \rm \sqrt{13 \times 13}$

$= \rm 13$

$\large\dag \large { \red{\underline{\bf{Hence }}}}$

• $\green{\textrm{Option (a) is correct}}$✓

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