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Maths question (Function 2)
Let f (x) = x - 3 & g (x) = 3 - x
Write the function (calculate step by step):
i) f ( g (x) )
ii) g ( f (x) )
Wrong answers by Mr. Knowledge:
f (g (x) ) should invariably equate to g (f (x) ).
U may substitute these unknowns f, g, x to prove.
Sorry yor~ Mr. Knowledge:
It should be my own misunderstanding !
In general, f (g (x) ) = g (f (x) ).
Yet, this time, it's conditional with those "let" substitutes !
Only (ii) has a careless mistake in your answer.
3 個解答
- 1997年7月1日Lv 51 十年前最愛解答
圖片參考：http://i256.photobucket.com/albums/hh172/hkchelsea...
If you have any questions, please feel free to ask.
資料來源： My Maths knowledge - TabbyLv 41 十年前
It shouldn't be big~ Just a little mistake~ Yet, your helping action is so quick~ TKS anyway !
- ?Lv 71 十年前
i) f[g(x)]
= f(3-x)
= (3-x) - 3
= -x
ii) g[f(x)]
= g(x-3)
= 3 - (x-3)
= 3 + 3
= 6
2010-10-12 18:22:39 補充：
Lol, I made a big careless mistake in (ii)
資料來源： Knowledge is power.
