假设f(x)= -3x + 2,你如何找到f(1/3)的值?
F(1/3)= 1 f(1/3)仅表示在x = 1/3处评估函数。因此,我们需要做的就是将1/3插入等式:f(1/3)= - 3(1/3)+2 f(1/3)= - 1 + 2 f(1/3)= 1
函数f定义为f(x)= x /(x-1),你如何找到f(f(x))?
每x替换f(x)然后简化。给定:f(x)= x /(x-1)每个xf的替换f(x)(f(x))=(x /(x-1))/((x /(x-1)) - 1)以(x-1)/(x-1)f(f(x))=(x /(x-1))/((x /(x-1)的形式将分子和分母乘以1 )-1)(x-1)/(x-1)f(f(x))=(x)/(x-x + 1)f(f(x))=(x)/ 1 f(f (x))= x这意味着f(x)= x /(x-1)是它自己的逆。
你如何找到f ^ -1(x)给定f(x)= 2x + 7?
F ^ -1(x)= 1/2(y-7)给定:f(x)= 2x + 7设y = f(x)y = 2x + 7用y表示x给出x的倒数y-7 = 2x 2x = y-7 x = 1/2(y-7)因此,f ^ -1(x)= 1/2(y-7)