andyyeung0912召喚!
唔識計=-= =.=咁似延數的,不過好似仲有幾課先幫到你...而且唔識英文....=.=好似講左好多廢話 數學我是愛莫能助:49;我CE無A MATH, AL無任何MATH:49; =.=咁似延數的,不過好似仲有幾課先幫到你...而且唔識英文....=.=好似講左好多廢話
vbnn20 發表於 2010-2-24 09:57 PM https://bbs.tennyy.com/images/common/back.gif
果d p maths黎.
本帥打救你
a)
f'(x )=1/4x^(-3/4)-1/4 =1/4 f'(x ) = 0 for x=1 <0 for 1<x<inf. >0 for 0<x <1 therefore, f(x ) attains its max at x=1 for all x?(0,inf.) because f is cont. on [0,inf.) , => f(x ) <= f(1 ) x^1/4 - 1/4x -3/4 <=0
replace x by x/y >=0 (x/y)^1/4 <= 1/4(x/y)-3/4 x^1/4 * y^3/4 <= 1/4x -3/4y
b)
since F and G are non-negative, i.e. F(x ) >=0 and G(x )>=0 by a, sub x=F(x ) , Y= G(x ) ^1/4 *^3/4 <= 1/4 F(x ) +3/4G(x ) in(a->b) ^1/4 *^3/4 dx <= in(a->b) 1/4 F(x ) +3/4G(x ) dx =1/4*1+3/4*1 =1/4+3/4=1 打到亂碼咁= =果然係神人... 我不是神.....
我只是小小的天使;] 呢題最難o既唔係條數,而係英文(對我來說:20;) 看來我的名字對你而言也不容易吧a"a!! 果d p maths黎.
本帥打救你
a)
f'(x )=1/4x^(-3/4)-1/4 =1/4 f'(x ) = 0 for x=1
angelliu 發表於 2010-2-24 10:42 PM https://bbs.tennyy.com/images/common/back.gif
哇 完全唔知你打緊d咩.... 呢d數對我來說真係深,看來我的數會愈來愈差
我連恆等式都未搞清楚
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