AP EAMCET202319 May 2023Morning ShiftMathematicsBinomial TheoremActual
The coefficient of x^2 in the expansion of (1-3 x)^ -1 / 4 is
Options
- A45 64
- B45 8
- C45 16
- D45 32
Correct answer
D. 45 32
Step-by-step solution
aligned & (d) (1-3 x)^ - 1 4 & =1+ (- 1 4 )(-3 x)+ (- 1 4 ) (- 1 4 -1 ) 2 ! (-3 x)^2+ & =1+ 3 4 + ( 1 4 ) ( 5 4 ) 2 ! (9) x^2+ & Hence coefficient of x^2= ( 1 4 ) ( 5 4 )(9) 2 ! = 1 2 ( 45 16 )= 45 32 aligned