the functions f and g are definded by
f:x→x^2+3 , x∈R
g:x →2x+1, x∈R
a)Find, in a similar form ,the function fg .
b)Find the range of the function fg .
c)Solve the equation
f(x)=12g^-1(x)
數學function
2011-10-02 4:17 am
回答 (2)
2011-10-02 5:45 am
✔ 最佳答案
(a) fg = (2x + 1)^2 + 3(b) Since (2x + 1)^2 >= 0, the range of fg is [3, infinity)
(c) g^(-1)(x) = (x - 1)/2
f(x) = 12g^(-1)(x)
x^2 + 3 = 12(x - 1)/2
x^2 + 3 = 6x - 6
x^2 - 6x + 9 = 0
x = 3
2011-10-02 5:18 am
Do you mean f(x) g(x) or f[g(x)] by fg?
收錄日期: 2021-04-26 14:54:58
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20111001000051KK00866