SHE'S THE ONE - SATZU (BOOK 1)

Chapter 25

"No, nothing."

"Ah, are you going to go home tomorrow??."

"Why? Do you want me to stay here again???."

"If it's okay???."

"Okay, but I'll go back to my unit first to get some clothes and then I will going  to check Nâinai's unit.."

"Your father allow you????." Sana excitedly asked.

"Yes Dad allow me. Dad actually told me that the idea I came up with was okay so that I could visit Nâinai more easily and so that she wouldn't be alone."

"Whoa, I'm so excited. I will always visit her unit if she's here already."

"That will be fine (´∩｡• ᵕ •｡∩')  I'm sure Nâinai will be happy to hear my good news for her."

"For sure, she is Tzu (*˘︶˘*).｡*♡ Nâinai is so lucky to have you as her granddaughter because you're so sweet and caring..."

"I'm also lucky to have her as my Nâinai."

-

After they had their grocery shopping they immediately went back to Sana's unit.

"I will in-charge in the kitchen, Just continue studying (´∩｡• ᵕ •｡∩') ..."

"Are you sure???."

"Yes."

"Arasso."

Sana change her clothes and continue studying on her desk while Tzuyu is at the kitchen preparing for their dinner.

While she's busy cooking her phone suddenly ring so she check who the caller is.

.
.
.
.
.
.
.

Nancy
Is Calling
You
Answer | Reject

Tzuyu:
Why???

Nancy:
Nothing. I just missed you.

Tzuyu:
Nancy, what do you really want???

Nancy:
You.

Tzuyu:
I told you, I don't like you.
Please stop bothering me.

Nancy:
You like me before.

Tzuyu:
I like you as a friend.

Nancy:
I can't accept that.

Tzuyu:
I'm in a relationship already.

Nancy:
Really

Tzuyu:
Yeah, so I appreciate if you will not bother me.

Nancy:
I don't believe you.

Tzuyu:
It's up to you wether you believe me or not. I still have a lots of things to do.

Tzuyu:
Bye.

-

When Tzuyu is done preparing the dinner she enter Sana's room to check the latter.

"Daebak, Why I can't get this." Sana mumbled as she scartch her forehead..

Tzuyu smile as she walks closer to her.

"May I help you????."

"You're done??."

"Mmmmm.." Tzuyu seated beside Sana. "What's your problem???." Tzuyu asked as she get the paper.

"It's Mathematics, my head is aching already and I still can't get the answer." Sana frustratedly said.

"This is easy."

"Eh?."

"Listen. f(x) is defined for all values x in R except x = π/2 + k * π, where k is an integer. Since tan(x) is periodic, then f(x) = arctan(tan(x)) is also a periodic function.
As x increases from -π/2 to π/2 exclusive, tan(x) increases from infinitely small values (- infinity) to infinitely large values (+ infinity) and arctan(tan(x)) increases from -π/2 to π/2 exclusive since tan(x) is undefined at -π/2 and + π/2. In fact for x in (-π/2 , π/2) arctan(tan(x)) = x.
Since tan(x) has a period of &π;, arctan(tan(x)) also has a period of π."

While Tzuyu is busy explaining to Sana, the latter was also spacing out as she mesmerized to Tzuyu's beauty. Everything suddenly went to a slow motion as she only see Tzuyu..

"Here, The graph below shows the graphs of arctan(tan(x)) and tan(x) from -π/2 to 3π/2."

Tzuyu suddenly stop explaining when she noticed that Sana is not reacting so she look at her and she saw the latter was just staring at her..

"Do you understand???.." Tzuyu asked, and this made Sana back to the reality.

"Huh?."

"The derative, the one that I explain. Did you understand?..."

Sana smile as she cling her hand to Tzuyu's arms.

"Tzuyu ~ ah ..." Sana cutely whine.

"Mmmmm????."

"Nothing..."

"Ya, You didn't understand what I'm explaining. Do you???."

"Numbers hates me." Sana pout.

"Aigooo... You should study this so that you will get it."

"Arasso. "

"But if you really don't understand then you must go to other subject. Don't focus here so that you will not wasting time."

"Okay (*˘︶˘*).｡*♡.."

"And please stop daydreaming.."

"Why🥺.."

"You are not really listening earlier. you're spacing out."

"It's your fault." Sana pout.

"And now you're blaming me.."

"You're just too gorgeous 😁 that I can't even take my eyes off you."

"You're so adorable.." Tzuyu said as she gently pinch Sana's cheeks while the latter just continue being clingy to Tzuyu.

xxxxxx