一道高数题 Find A and B given that the function f(x) is differentiable_数学解答

一道高数题 Find A and B given that the function f(x) is differentiable at x=1
f(x)= x^3 (x1)

人气：317 ℃　时间：2020-03-24 08:24:57

解答

因为可导所以在x=1时两个表达式极限相同,两个表达式的导数的极限也相同,即：
lim f(x) at x=1 gives
1^3=A*1+B => A+B=1
lim f'(x) at x=1 gives
3*1^2=A => A=3, so B=-2