[Solution (2): The problem is equivalent to f(x)=1 and there are only two solutions in (0,+∞). 】

[When 00, so x-a/l.]

a>0, so f'(x)>0, so f(x)=1 has at least one solution, so a>1. 】

[At this time, l

a>0，a/l

a>0, change the f(x) definition field to [0,+∞, in which case f(0)=0. 】

【……】

[Let g(x)=x-1-l.]

x，x∈（0，+∞），g’(x)=1-0-1/x=(x-1)/x。 】

So g(x)≥g(1)=1-1-l

1=0。 】

[L is obtained from a>1.]

a>0 to get: g(l

a)≥0。 】

[...... by Bo's effort inequality]

[From the monotonicity of f(x), it can be seen that f(x)=1, in (0, a/l

a) and (a/l.)

a, +∞). ]

[In summary, the value range of a is (1,e)∪(e,+∞). 】

……

It's that simple when it's done.

The focus of this question is nothing more than the application of knowledge points such as derivation, isomorphism, and extreme point offset.

Here, Lin Bei also used Bernoulli's inequality, which everyone must know, right?

Bernoulli's inequality, also known as Bernoulli's inequality, is a scaling of a power function to a primary function.

It may not be used very much on weekdays.

However, in the finale question of the college entrance examination, especially in the second question, there are many opportunities to use it.

Of course, it is not necessary to use Bernoulli's inequality to make the second question of the finale of this volume.

In fact, there are many more ways to do it.

As long as you know enough about isomorphism, exponential tangent contraction, and hidden zero points, you can see it at a glance by drawing it.

Besides.

The Lopida Law can also be used.

However, high school doesn't seem to learn the law of Lopida, which belongs to the knowledge of the university, so the general teacher does not allow it to be used, unless you prove it yourself, otherwise there is a high probability that points will be deducted.

All in all.

This derivative finale is difficult for ordinary people.

But when it comes to the height of Lin Bei, is it difficult?

The clock on the blackboard points to 2:28, just five minutes after the end of the previous question.

The derivative finale is done in five minutes.

Ignorance...... Have you ever seen one?

This kind of hand speed, don't say that you have been single for 1,000 years, even if you have been single for 10,000 years, I am afraid that it is beyond reach!

"Whew, this roll is really boring!"

Lin Bei exhaled lightly, and there was a feeling of loneliness between his eyebrows.

It's really that these questions are too simple, even if it's the finale, he doesn't need to think too much.

It is no exaggeration to say that the only thing that limits his exam speed is his hand speed, otherwise it can be faster.

Originally, he was full of expectations for this exam.

After all, this was the first formal exam he took after being reborn, and he wanted to test his strength.

But now, I feel a little disappointed.

"This year's questioners are not very good, right?"

"Even if the Chinese problems in the morning are simple, the math problems are the same now, and I feel like fooling people."

"Don't tell me you're sending schoolchildren away?"

“ヽ(｀⌒´メ)ノ！”

Lin Bei spread his hands and set his eyes on the last two questions of the test paper, that is, the optional questions.

Optional questions.

As the name suggests, just choose one.

Do whatever you know, and don't try to do them all, because that's useless.

If you do all of them, you will only be scored according to the first question when grading, which will only waste the candidate's time.

However, the most important thing Lin Bei lacks now is time.

After all, the math test is 120 minutes, and it has only taken him 28 minutes to do it now, which is less than half an hour.

So......

Two questions, he killed them all in one go.

Saw......

Question 22, coordinate system and parametric equation.

Question 23, Selected inequalities.

Many test takers tend to fall into a misunderstanding of tangled thinking when they see the last two optional questions.

Is this the choice of coordinate system and parametric equation? Or do you choose to choose an inequality selection?

Some people say that the former is the best.

Because this question is scored by points, even if you don't know all of them, you can write one or two, but the inequality is different.

Some people say that the latter is the best.

Is it an inequality after all?

The first question is the routine of sending points.

The second question is that although there are many changes, there is no escape from those formulas, such as the changes in Cauchy's inequality.

All in all.

It is the public who says that the public is reasonable, and the mother-in-law who says that the mother-in-law is reasonable.

No one can win the fight, so that more people have a headache.

But Lin Bei naturally didn't need to dwell on these, after all, he had solved both questions without much effort.

2:30 min, Coordinate System and Parametric Equation, Death.

2:32 minutes, inequality selection, death.

Two minutes together, adding up to only four minutes.

Don't ask him why he's so fast, because his strength is tough enough, strong enough, and naturally domineering.

And then.

He threw himself on the table and fell asleep again.

Recuperate and prepare for the next communication with Zhao Qinghan after the exam, isn't it too much?

Invigilator: "←_←??" ”

Nearby classmates: "→_→??" ”

Seeing this scene, everyone was speechless.

"He slept, and he slept again?"

"In the morning Chinese exam, Lin Bei just slept forty or fifty minutes after the exam, and now the math test has only been more than half an hour, and he actually sleeps on the table again?"

"This ...... Isn't it incredible? ”

"No matter how strong he is, he can't do it so quickly, right? Unless he doesn't know anything, it's just cool. ”

"Sure enough, Lin Bei is still the former Lin Bei, a bad person for one day, a bad person for life, and the nature of learning water is difficult to change."

"Thirty minutes, it is a miracle to be able to take the test for thirty points, this time he made a bet with Yang Juntian, and it is estimated that he will lose."

“……”

Many in the class shook their heads.

Including Zhang San, Li Si, Wang Teng and Zhao Dali.

Originally, Lin Bei's performance in the past half a month was very good, and he had been studying hard, and everyone thought that there might really be a close battle between him and Yang Juntian.

But as a result, the evenly matched forces didn't see it, and the light saw Lin Bei sleeping and breaking the jar.

Even though this is only the second subject, and the science and foreign language have not started, everyone can already expect the ending.

Yang Juntian must be in the top ten of the class.

Rush and maybe make it to the top five.

The total score shall not be less than 600 points.

And Lin Bei's ironclad countdown, the total score of the six subjects can break 100, and the sun comes out of the west.

on this.

The happiest and proudest is undoubtedly Yang Juntian.

He almost laughed like a pig in the previous language exam, and he couldn't even cover it.

"Lin Bei, I really think highly of you!"

"I was a little worried before the exam, but now it seems that I won this game!"

"When the time comes, you will obediently sing to me in front of the whole school teachers and students, and shout for Ultraman Tiga!"

"After you are out of appearance and lose face, I see how you still have a face to entangle Zeng Xi!"

"Ahh