,what is the coeicient of (x+2)^3?
1 Answer
Mar 10, 2018
Explanation:
#"using the "color(blue)"Taylor series expansion"#
#•color(white)(x)f(x)=sum_(n=0)^oo(f^n(a))/(n!)(x-a)^n#
#=f(a)+(f'(a))/(1!)(x-a)+(f''(a))/(2!)(x-a)^2+(f'''(a))/(3!)(x-a)^3+...#
#"here "a=-2#
#"here we require the coefficient of "(x+2)^3#
#"that is "(f'''(a))/(3!)(x+2)^3#
#"the coefficient "=(f'''(-2))/(3!)#
#f(x)=e^x#
#rArrf'(x)=f''(x)=f'''(x)=e^x#
#rArrf'''(-2)=e^-2=1/e^2#
#rArr(f'''(-2))/(3!)=1/e^2 xx1/6=1/(6e^2)#