Page 211 - aljaber
P. 211
@ @¶ìÿa@óÝy‹¾a@ u@ @QYX
2 γβα
α+β +γ
) α=2
.(
β + γ = 16 = 3 + 13 = 5 + 11
γ = 13 β = 3 .
αβ + βγ + γα = 2 × 3 + 3 ×13 + 13 × 2 = 71 ()
. γ = 11 β = 5 .
.k = 2 × 5 ×11 = 110
:( )
f (−7) = −77 ×a − 73 ×b − 7c − 5 = 7
⇒ 77 ×a + 73 ×b + 7c = −12
. f (7) = 77 ×a + 73 ×b + 7c − 5 = −12 − 5 = −17 )
:( ) (
x 3 + px2 + qx + 15 = (x − α1 )(x − α2 )(x − α3 )
( )= x2 − (α1 + α2 )x + α1α3 (x − α3 )
( )= x2 + α1α3 (x − α3 )
= x 3 − α3x 2 + α1α2x − α1α2α3
.−α1α2α3 = +15 α1α2 = q p = −α3
. pq = −α1α2α3 = 15
x2 − 9 f (x) :( ) ()