For what ___ did he come here.

why
副词 adv.
1.（用于问句）为什么,为何
Why are you late?
你为什么迟到?
Why not call on me tomorrow?
你干吗不明天就来看我呢?
That is why I'm working hard at my lesson.
就是这个原因, 我要努力学习.
I can't understand why he failed.
我不明白他为什么失败了.
That is the reason why we must go now.
那就是我们现在必须走的理由.
Why ever didn't you tell us before?
你怎么不早告诉我们呢?
2.（反问,表示不必）何必
3.（说明理由）为什么,…的原因
感叹词 interj.
1.呵唷, 哎呀, 嗨
Why, what's the harm?
嗨, 这又有什么害处呢?
名词 n.
1.理由；原因；缘故
what for
为什么
67.Guess. 猜猜.
68.what for? 为什么?
69.Wait a minute. 等一会儿.
为何
what follows 下列所述
what for 为何
what is called 所谓
干什么
一些书写纸some writing paper
干什么? what for?
写一封信 write a letter
为什麽
You really ought to take some time off. 的确应该休一休假.
what for? 为什麽
To enjoy the simple things in life ... 享受人生乐趣……

铅笔：你知道,我真的很抱歉.
橡皮擦：为什么,你没做错什么?
铅笔：对不起,因为我使你受到伤害.每当我犯错,你总是在那里帮我擦掉,但是当你为我改错时,你就失去了你自己一部分.你每次变得越来越小.
橡皮擦：确实,但我真的不介意.你知道我是用来做这样的事的.我生来就是当你犯错时帮助你的.即使我知道某天我会消失和被代替,但我真的很开心.因此,别担心.我害怕你悲伤.
原文有些拼写错误.希望对你有用.

1.可以引导原因状语从句：for表现的因果关系不像because那样强烈,它引导的原因状语从句并不说明主句行为发生的直接原因, 只提供一些辅助性的补充说明,例如： He could not have seen me, for I was not there. 他不可能见过我, 因为我不在那里.
2.也可以引导定语从句
3.理论上是可以回答Why的,但是一般和Why对应的是because

我会在这,为什么?我要在这等,等谁?我会在这等你.所以,如果你来到这里,你一定会看到我.我保证.
要注意的是这里的for what不是为了什么,它是依据wait for这个语法问的,应该是等谁的意思.还有这里的find翻译为找到不合适,其实它也有“看到”的含义,更贴切.

答案：A
这个无法解释,都是固定搭配,死记而已.
(get/be paid) by hours 按（小）时取酬
(get/be paid) by the month 按月取酬
by weight 按照重量

方便起见换一下字母:X³+Y³+Z³+mXYZ = 0.
题目没有说明是在那个域上讨论的,以下讨论适用于特征不等于2,3的域K.
分为两种情况:①x²+x+1 = 0在K上无解,K中的3次单位根只有1;
②x²+x+1 = 0在K上有解,设ω是一个解,K中的3次单位根有1,ω,ω².
曲线的奇点满足方程组3X²+mYZ = 3Y²+mXZ = 3Z²+mXY = 0.
若X,Y,Z中有0,易得X = Y = Z = 0,不对应P²中的点.
故只需考虑XYZ ≠ 0,而由方程可得m³X²Y²Z² = -27X²Y²Z²,因此m³ = -27.
而当m³ = -27,易见(-3:m:m)总是曲线的奇点.
因此曲线非奇异的充要条件是m³ ≠ -27.
对情况①,这等价于m ≠ -3; 而对情况②,这等价于m ≠ -3,-3ω,-3ω²
曲线的Hessian判别式det([6X,mZ,mY;mZ,6Y,mX;mY,mX,6Z]) = (216+2m³)XYZ-6m²(X³+Y³+Z³).
与X³+Y³+Z³+mXYZ = 0联立得8(27+m³)XYZ = 0.
而m³ ≠ -27,故XYZ = 0.分别将X = 0,Y = 0,Z = 0代回方程可求得拐点.
对情况①,在K上有3个拐点:(0:1:-1),(1:0:-1),(1:-1:0).
对情况②,在K上有9个拐点:
(0:1:-1),(1:0:-1),(1:-1:0),(0:1:-ω),(1:0:-ω),(1:-ω:0),(0:1:-ω²),(1:0:-ω²),(1:-ω²:0).

不要对他寄予太多,这最终只是一个幻想,因为不管他做什么,都只会带给你失望.
A为动词,其他选项用意思可以排除

1.Dad,can I have a walkman?爸爸,我可以要个随身听吗?2.For what?用在哪里?3.I want to listen to English.我想听英语.4.That's OK.好的5.What can I do for you?有什么可以帮你吗?6.I want to buy a walkman.我想...

当然能用,没错

1.let f be the function given by f(x)=2e^(4x^2).for what value of x is the slope of the line tangent to the graph of f at( x,f(x) ) equal to
A.0.618 B.0.276 C.0.318 D.0.342 E.0.551
【Solution】：
df/dx = 16xe^(4x²)
Let df/dx = 3
We get e^(4x²) = 3/16x,
By GC,x = 0.17
Ans:None of the above.
2.a railroad track and a road cross at night angles.an observer stands on the road 70m south of the crossing and watches an eastbound train traveling at 60m/s.at how many meters per second is the train moving away from the observer 4 seconds after it passes through the intersection?
A.57.60 B.57.88 C.59.20 D.60.00 E.67.40
【Solution】：
Let x be the distance between the train and the junction(intersection).
Let r be the distance between the train and the observer.
So,r² = 70² + x²
2rdr/dt = 2xdx/dt
t = 4 sec,x = 4×60 = 240 (m/s),r = √(4900 + 57600) = 250 (m)
∴ dr/dt = 240×60÷250 = 57.60 (m/s)
Ans :A
3.if the derivate of f is given by f ' (x)=e^x-3x^2,at which of the following values of x does f have a relative max value?
A.-0.46 B.0.20 C.0.91 D.0.95 E.3.73
【Solution】：
∵df/dx = e^x -3x²,
∴d²f/dx² = e^x -6x
Let df/dx = 0,x₁= -0.46,x₂= 0.91 (By GC)
d²f/dx²|(x₁) = 3.39 > 0 (Rej)
d²f/dx²|(x₂) = -2.98 < 0
Ans:C
4.At time t≥0,the acceleration of a particle moving on the x-axis is a a(t)=t+sint.at t=0,the velocity of the particle is -2.for what value of t will the velocity of the particle be zero?
A.1.02 B.1.48 C.1.85 D.2.81 E.3.14
【Solution】：
a = dv/dt = t + sint
v = ½t² - cost + c
-2 = 0 - 1 + c,c = -1
v = ½t² - cost - 1
Let v = 0,
ie.½t² - cost - 1 = 0
t₁= - 1.48 (s) (Rej)
t₂= + 1.48 (s)
Ans:B

没有固定说法,每个人有每个人的习惯,一般是名词的缩写多些

选C,For whom 给谁的

他们遵循规则是为了什么?

B
有一个词组叫 for the purpose of

老人讨厌城市的噪音.表示情感,用一般时

e tired of是厌倦的意思；be tired with“因.而疲劳”,好像没有be tired for结构.
what for一定情况下可以与why互换
例如 why did you go there?等同于 what did you go there for?
for what意为“为了什么”.例如：
For what do we live?

what for是你做这个是了为什么,也可以询问工具有什么用途
for what是为了什么你这么做
其实差别不是也不是很大