Question
Use identities to evaluate : $(998)^2$
✓
Answer
$(998)^2$
$(998)^2 = (1000 - 2)^2$
We know that
$( a - b )^2 = a^2 + b^2 - 2ab$
$\therefore (1000 - 2)^2$
$= 1000^2 + 2^2 - 2 \times 1000 \times 2$
$= 1000000 + 4 - 4000$
$= 9,96,004$
$(998)^2 = (1000 - 2)^2$
We know that
$( a - b )^2 = a^2 + b^2 - 2ab$
$\therefore (1000 - 2)^2$
$= 1000^2 + 2^2 - 2 \times 1000 \times 2$
$= 1000000 + 4 - 4000$
$= 9,96,004$
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