AP EAMCET202318 May 2023Evening ShiftMathematicsBinomial TheoremActual
Let x be a real number and -2 < x < 2 . When x 1 (x+3)(x-2) is expanded in powers of x , then the coefficient of x^3 is
Options
- A- 55 1296
- B- 97 216
- C- 13 216
- D- 119 1800
Correct answer
A. - 55 1296
Step-by-step solution
aligned & x+1 (x+3)(x-2) = 3 5 1 (x-2) + 2 5 1 (x+3) & =- 3 5 2 (1- x 2 )⁻¹+ 2 5 3 (1+ x 3 )⁻¹ & x+1 (x+3)(x-2) =- 3 10 (1+ ( x 2 )+ ( x 2 )^2+ ( x 2 )^3+ ) & + 2 5 (1- ( x 3 )+ ( x 3 )^2- ( x 3 )^3+ ) & The coefficient of x^3=- 3 10 ( 1 2 )^3- 2 15 1 27 & =- 55 1296 aligned