函数f(x)=2^x(ax^2+bx+c)满足f(x+1)-f(x)=2^x*x^2(x∈R),求常数a、b、c的值

来源:学生作业帮助网 编辑:作业帮 时间:2024/05/07 21:53:51
函数f(x)=2^x(ax^2+bx+c)满足f(x+1)-f(x)=2^x*x^2(x∈R),求常数a、b、c的值

函数f(x)=2^x(ax^2+bx+c)满足f(x+1)-f(x)=2^x*x^2(x∈R),求常数a、b、c的值
函数f(x)=2^x(ax^2+bx+c)满足f(x+1)-f(x)=2^x*x^2(x∈R),求常数a、b、c的值

函数f(x)=2^x(ax^2+bx+c)满足f(x+1)-f(x)=2^x*x^2(x∈R),求常数a、b、c的值
f(x)=2^x(ax^2+bx+c)
f(x+1)-f(x)=2^x*x^2
2^(x+1)[a(x+1)^2+b(x+1)+c] - 2^x(ax^2+bx+c) = 2^x*x^2
2*2^x * [ax^2+(2a+b)x+a+b+c] - 2^x(ax^2+bx+c) = 2^x*x^2
2*2^x *ax^2+2*2^x *(2a+b)x+2*2^x *a+2*2^x *b+2*2^x *c - 2^x*ax^2-2^x*bx-2^x*c = 2^x*x^2
a*2^x*x^2+(4a-b)*2^(x+1)+2^x(2a+2b+c) = 2^x*x^2
a=1
4a+b=0,b=-4
2a+2b+c=0,c=-2+8=6