Most Important Selected Qs for JEE AdvancedMathematicsBinomial Theorem
Match the following ( array ll Column-I & Column - II array l (A) If (x+ 1 x +x^2+ 1 x^2 )^9=a₀ x⁻¹⁸+a₁ x⁻¹⁷+ .+a₃₆ x¹⁸, then (a₀+a₂+ .+a₃₆ ) is equal to array & (p) 2²⁴ (B) If (1+x+x^2+x^3 )³³=a₀+a₁ x+a₂ x^2+ . .+a_ 3 g x³³, then (a₀ . & (q) (18 2¹⁹+1 ) (C) ²⁰ C ₂+2 ₂+ ²⁰ C ₁₂+3 + ₃ ²⁰ C ₄+ +19 ²⁰ C ₂₀ is equal to & (r) (2^8+2¹⁷ ) (D) ²⁰ C ₁+2 ²⁰ C ₂+3 ²⁰ C ₃+4 ²⁰ C ₄+ . .+10 ²⁰ C ₁₀ is equal to & (5) 20 (2¹⁸+ ¹⁹ C
Options
- A( A ) ( s ) ;( B ) ( r ) ;( C ) ( t ) ;( D ) ( p )
- B( A ) ( p ) ;( B ) ( r ) ;( C ) ( s ) ;( D ) ( t )
- C( A ) ( r ) ;( B ) ( p ) ;( C ) ( q,t ) ;( D ) ( s )
- D( A ) ( q ) ;( B ) ( s ) ;( C ) ( p ) ;( D ) ( r )
Correct answer
C. ( A ) ( r ) ;( B ) ( p ) ;( C ) ( q,t ) ;( D ) ( s )
Step-by-step solution
(A) (x+ 1 x +x^2+ 1 x^2 )^9=a₀ x⁻¹⁸+a₁ x⁻¹⁷+ . .+a₃₆ x¹⁸ Put X =1 and -1 , and odd We get. (a₀+a₂+ . .+a₃₆ )= (2^8+2¹⁷ ) (B) (1+x+x^2+x^3 )¹³=a₀+a₁ x+a₂ x^2+ . .+a₃₉ x³⁹ Put fourth roots of unity, 1, , ^2, ^3 and add together We get. (a₀+a₄+a₈+a₁₂+ . .+a₆₆ )= 2²⁶ 4 =2²⁴ (C) ²⁰ C ₂+2 . ³⁰ C ₃+3 ²⁰ C ₄+ . .+19 . ²⁰ C ₂₀ Let (1+ x )²⁰= ²⁰ C ₀+ ²⁰ C ₁ x + ²⁰ C ₂ x ^2+ + ²⁰ C ₂₀ x ²⁰ divide by x , and differentiae both sides, ( ²⁰ C ₂+2 ²⁰ C ₃+19 ²⁰ C ₂₀ )= (18 2¹⁹ )+1 (D) aligned & ²⁰ C ₁+2 . ¹⁰ C ₂+3 ²⁰ C ₃+4 . ²⁰ C ₄