-
[ ( 1.7 )3 - ( 0.7 )3 - 3 × 0.7 × 1.7 ]/[ ( 3.6 )2 + ( 0.6 )2 - 2 × 3.6 × 0.6 ] का मान है
-
- 1/3
- 1
- 1/32
- 1/33
सही विकल्प: C
[ ( 1.7 )3 - ( 0.7 )3 - 3 × 0.7 × 1.7 ]/[ ( 3.6 )2 + ( 0.6 )2 - 2 × 3.6 × 0.6 ]
[ ∴ a2 + b2 - 2ab = ( a - b )2 तथा a3 - b3 = ( a - b ) ( a2 + b2 + ab ) ] ( सूत्र )
= [ (1.7 - 0.7 )( 1.72 + 0.72 + 1.7 × 0.7 ) - 3 × 0.7 × 1.7 ]/( 3.6 - 0.6 )2
= [1(1.72 + 0.72 + 1.7 × 0.7 ) - 3 × 0.7 × 1.7 ]/( 3 )2
= [ (1.72 + 0.72 + 1.7 × 0.7 ) - 3 × 0.7 × 1.7 ]/9
= [ 1.72 + 0.72 - 2 × 0.7 × 1.7 ]/9 = ( 1.7 - 0.7 )2/9 = 1/9 = 1/32
अतः व्यंजक का मान 1/32 होगा।
