“...... Yes, young master!" Linghua replied—the smile on her face became a little stiff. And Haitang looked surprised, and knelt on the ground and shouted loudly: "Young Master Xie, Young Master Xie for your grace!"

——

Shenmu City, the backyard of the 'Wind and Ni World' spirit rune shop.

Yun Ni, who was dressed in a magic robe, sat on a chair and pointed to a puzzle and asked, "Zang Feng, what do you say is the matter with this natural base e? How can you come up with such a number that has no rules at all?"

Liang Feng responded: "This natural base e is a bit similar to pi π - pi π can be understood by circumcision: assuming that the diagonal length of an isolateral is one, as long as there are enough sides of the isolateral, the calculated circumference of the isolateral is getting closer and closer to the π of pi." ”

"The discovery of the natural base e may be related to the interest in ancient times: suppose I lend you a spirit stone, and the annual interest rate is agreed to be ten out of ten, then if you pay the interest once a year, I will have two spirit stones in a year; If I pay the interest once an hour or every instant, how many spirit stones can I get in a year?"

“...... How many spirit stones? There should be a lot of them, right?" Yun Ni asked as she looked at Liang Feng with bright eyes.

"No, at most this natural base E - roughly 2.71828 blocks. ”

"That'...... So what's the use of this natural number e?"

Liang Feng responded: "Very useful - the logarithm of using e as the base is usually more concise and direct than other bases! For example, the second layer of the 'unpredictable illusion technique' of this fixing problem, you need to open the square of the large number, if you do not apply the logarithmic calculation of the natural base, the amount of calculation is amazing, and the logarithmic calculation of the natural base plus the logarithmic table that can be pre-calculated, the mental arithmetic can calculate the result." As he spoke, he remembered the golden years of mathematicians in his memory of his previous life—

It was the beginning of the Great Voyage, because there was no accurate clock, it was difficult for merchant warships sailing on the sea to determine their longitude, so people turned their eyes to the sky and used star maps and sextants to determine their longitude - in this way, astronomers and mathematicians of that era took center stage, and they could gain fame and fortune by calculating and predicting the orbits of stars and making accurate star maps. At that time, mathematics took a big step forward, and logarithms, analytic geometry, calculus, etc., were all proposed in that era in order to solve problems.

After a pause, he gave an example: "Also, there are many indirect examples of natural bases in nature - for example, logarithmic spirals!" As he spoke, Liang Feng took out a flower of an elixir from the storage bag, pointed to the layers of bright petals and said, "Look at the angle between the continuous line of petals and the rays emitted from the center of the flower bud, is it all the same?"

Turning her head and looking at Liang Feng sitting next to her for a moment, Yun Ni smiled bitterly: "Zang Feng, Master, I'm really stupid - after five years, I still can't learn these advanced embellishment techniques, and I can't practice the second layer of the 'Unpredictable Illusion Technique'." ”

Liang Feng comforted: "Master, in fact, you are already the second most powerful person I have ever taught, much more powerful than Chen Ying and Lingrui...... He knew that this advanced embellishment technique was quite a test of people's talents-such as abstract ability, not that you can learn it if you want to.

"Really?!" Yunni was happy again, "Who's the first to be the best?"

Liang Feng responded: "It's a little fox, it's ...... I don't know where it went now. Thinking of the little fox Fei'er, his heart was much heavier.

"Zang Feng......" may have seen Liang Feng's face a little gloomy, Yun Ni stood up and turned around and sat in Liang Feng's arms, wrapped her hands around his neck, and shouted softly: "Zang Feng, Master, I love you!" and glamed his lips with his lips, and his tongue slid over-

Feeling that there was no other clothing under Yunni's fluffy robe, his two big hands went deep into her robe without hindrance, grabbed the two treasures that were flawless in shape and softness, and turned them into various shapes, and couldn't help but praise in his heart: "What a superb stunner that you never get tired of playing!"

Gradually, feeling the hardness of the top of the two treasures in his palm becoming more and more erect, Liang Feng chuckled: "Master, shall we sit here and have fun today......?"

Watching the robe slip down from Yun Nixiang's shoulders, revealing two white flowers, heavy treasures dancing up and down, and listening to the extraordinarily soft and unusually soft 'Uh-huh-......' sound like an attack horn, Liang Feng's blood boiled, and he ran the 'Bliss Joy Zen' exercise with all his might, and his waist trembled rapidly......

"Zang Feng, Zang Feng! Master, I ...... I went, went...... Go!" Yun Ni's body stiffened, as if she was holding Liang Feng tightly with all her strength, and after a while, she exhaled a long breath "Ah-" After a while, her body twitched for a moment, turning into a ball of soft mud and slumping on Liang Feng's body.

After holding Yunni for a moment of 'silent is better than sound', Liang Feng said softly: "Master, I will set off for 'Fallen Demon Island' in more than two months, and it is estimated that it will take four or five years to come back, you have to take care of yourself." ”

Although the 'Fallen Demon Island' has only appeared for about a month, it is located in a sea area between the 'Houtu Sect' and the 'Immortal Water Sect', which is quite far away from the Shenmu Sect, if you don't use the 'Teleportation Great Array', you may not be able to reach it for ten years - but Liang Feng heard that most of the way to the 'Fallen Demon Island' this time is to use the 'Teleportation Great Array', and the rest use large high-grade hurricane boats, and the time on the road is about two years.

"You...... Are you going to 'Fallen Demon Island'......? It's dangerous there!" Yunni was suddenly startled, and her blurred eyes immediately turned into surprise and worry.

"The ancestor of Dongfang Qingfeng has already issued an order, and being able to go to the 'Fallen Demon Island' is also a training opportunity, so I definitely have to go there. Liang Feng responded.

“...... That...... Then you must come back!" As he spoke, Yunni took his storage bag, poured all the contents on the table, and said softly: "Zangfeng, if you pick anything that can be used, take it with you." ...... Besides, I'd rather not have any treasures, and you have to come back safely! If anything is missing, we'll find a way to ......."

"You know, I'm not going to take unnecessary risks. Listening to Yun Ni's overflowing care and love, Liang Feng was moved and ashamed in his heart: "Alas, Shi Niang, she is infatuated with herself, and the Dongfang Qingfeng she plays is married to Shangguan Qiushui......"

After picking out a few more treasures on the table, Liang Feng was silent for a moment and said softly: "Senior Niang, Dongfang Qingfeng and Shangguan Qiushui are ...... ......"He felt that he still had to take the initiative to tell her about it.

“...... I...... I know...... I know......! It's not your fault, Zangfeng. There seemed to be a mist in Yunni's bright eyes.

“...... Alas, Shi Niang must have been a very proud person, but now she is so wronged by herself. With another pain in his heart, Liang Feng took out the sixteen-fold set of Spirit Gathering Array Flags and handed it to Yun Ni, and said, "Master, you can use this set of Spirit Gathering Array - I thought it would be enough for you to use that eightfold array, but now it seems that it is not enough." And he said, "I probably won't have time to come here again after that, so I'll ......."

Yun Ni pushed the Spirit Gathering Array Banner back to Liang Feng and said, "I don't want it! I just want you to return safely." ”

"Obedient!" Liang Feng pinched Yunni's slender waist, put the flag in her hand and commanded: "This Spirit Gathering Array can gather sixteen times the intensity of spiritual energy, it is very precious, it must be kept very strictly secret!"

He knew that sending the sixteen times the Spirit Gathering Array to Yun Ni in this way would increase the risk of exposure, but Yun Ni had been trapped in the enemy camp for decades and had been delayed for a lot of time, and now was the time when he needed this Spirit Gathering Array to speed up his cultivation, if he stood by and watched because he was afraid of taking risks, it was not the 'Dao' in his heart.

"How many times? sixteen times?" Yun Ni looked like she didn't believe her ears.

"Well, sixteen times!" Liang Feng's divine sense unfolded, and after sensing that there were no powerful people nearby, he set up the sixteen times spirit gathering array—a gust of wind instantly broke out in the room, and a milky white light cluster gradually condensed in the center of the circle, becoming thicker and thicker.

Yun Ni's eyes were full of shock, and he walked into the center of the magic circle and sensed it, muttering, "Really, really sixteen times?!"