Linear Algebra Exercise - Topic 2 of Machine Learning Foundations

[@Ossigen8]

hello, i'm 16 years old from italy, i've tried a lot of course on youtube for machine learning but they just didn't mean nothing to me, i was just using function of a library, then i cath this course and finally things is starting to get more sense, thank you. ps: i'm at the third year in highschool and we just arrived at the matrix in math, but i hope i can understand everything even if i'm not that good at math in school !

[@Hsnfci83]

So to follow Amount(Mark 1) =(T+30)* 1 ( Where T unit day) Amount(Mark 2) = T*4 So when both two amounts are equal (T+30) *1 = T*4 T+30 = 4T 30 = 4T-T 30 = 3T T=10 so after 10 days both amount should be equal which is on May 10th and the total amount will be generated is (10+30) + 4*10 = 80 kj and of course if they are generating both amounts per day there will be no intersection. Cheers Dr. Jon

[@MalhotraHarshika]

can you please explain me this

[@sarkersaadahmed]

why would you add?

[@munimshah3522]

I went... (1*30)+t=4t 30+t= 4t ---- ---- -t -t 30 = 3t ---- ----- 3 3 10=t 10 + 30 = 40 days aka May 10th Did it in my head like this. Didn't think it would be right, but it was. If anyone can explain why I would appreciate it!

[@utkarshdubey1570]

​@@MalhotraHarshika Ya I can .

[@nocap3154]

mine is day = (30 * t), day = (120 * (t-30) 30t = 120t - 3600 30t - 120t = -3600 -90t = -3600 t = 40 days so after 40 days (after mark 1) or 40-30 for mark 2, it will catch up and energy will be 40 * 1 for mark 1 or 4 * (40-30) for mark 2 which is 40kj.

[@finncollins5696]

hey Jon, got the answer. thanks once again for this tutorial series....

[@JonKrohnLearns]

Nice! Glad you found it :)

[@hcdebey]

It seems that there is a slight mixup of terms. At 2:04, It is stated that power is produced at 1 kJ/day. I believe that a kJ is a unit of energy, not power.

[@gauravsonawane7351]

Here is the way how I framed this problem: mark 1 make - 1kj => e1 = 1kj * days mark 2 makes - 4kj => e2 = 4kj * days find out when they would make equally same energy e1 = e2 (I don't know if here, I can say , LHS = RHS ) 1kj*days = 4kj*days solve it answer would be 40 days, to become equal, means to make equal energy and to find the total energy, yaa it's so easy >>---> replace days with 40 in above eq, [ no that 30 days ] And now you can solve I know. 😁

[@Alias.Nicht.Verfügbar]

thanks for the knowledge!

[@jamescarpenter3657]

Jon, I'm having trouble understanding when I would use parenthesis while using linear algebra to solve real world problems such as this. For example in this equation I can understand that -30 represents the days of the month that the Mark ll has effectively missed/skipped, and I can understand the 1KJ of power for the Mark l and the 4KJ of power for the Mark ll. With this, I initially thought the way to solve this problem was 1KJ = 4KJ - 30 rather than 1KJ = 4(KJ - 30). My question is, when I'm trying to think about a simple equation like this logically, how would I think to use parenthesis? In other words, how would you explain to me in very plain and simple English the parenthesis in this equation? EDIT - Ok this was super confusing for me but I think I figured it out... Could it also be 1(d+30) = 4d ? I had the parenthesis on the other side to start, but it just didn't make sense in my mind. Having it this way makes the think "the Mark l started a month early, so we are giving it an EXTRA 30 days rather than SUBTRACTING 30 days of power from the Mark l"... Are there any advantages or disadvantages by doing it this way? Jeez I just spent half an hour thinking about this... was bothering my brain...

[@gauravsonawane7351]

Hey Bro - I will definitely tell that your problem solving curiosity is just amazing, you found the brute way to solve eq, But here I am to help you, for how you can solve this like normal way: mark 1 make - 1kj => e1 = 1kj * days mark 2 makes - 4kj => e2 = 4kj * days find out when they would make equally same energy e1 = e2 (I don't know if here, I can say , LHS = RHS ) 1kj*days = 4kj*days

[@jamescarpenter3657]

@@gauravsonawane7351 Thank you for your help, I really appreciate it

[@gauravsonawane7351]

@@jamescarpenter3657 just asking, at what stage you are know , and what is your purpose for learning this, mine is to make computer vission for my gadgets: it would be cool and important for me so that's why i am learning ai ml

[@munimshah3522]

I went... (1*30)+t=4t 30+t= 4t ---- ---- -t -t 30 = 3t ---- ----- 3 3 10=t 10 + 30 = 40 days aka May 10th Did it in my head like this. Didn't think it would be right, but it was. If anyone can explain why I would appreciate it!

[@puneetsethi5738]

hey Jon, I got the answer to be: 1* t = 4* (t-31) 1T = 4t - 124 T-4t = -124 -3t = -124 => 41.33 what did i missed?

[@puneetsethi5738]

Never mind. April has 30 days. Silly mistake:);

[@shojalhalbe]

Easily done 👍

[@travail6920]

Mmm this needs a little explanation, no? Not just giving the solutons, at least gives us the x, y axis you used and where does the data fit in the y=ax+b

[@JonKrohnLearns]

Hi there, you should have enough information to solve this problem. Refer back to the sheriff/robber example I gave in this earlier video for some hints on how to get there: kzbin.info/www/bejne/hH63gmqopMmIrrs If you're still stumped, I provide a complete walkthrough to the solution of this solar panel exercise in my Udemy version of this course, which you can typically obtain very cheaply via this link: jonkrohn.com/udemy Hope that helps :)

[@yxcqwertzubn]

why you put that thing in front of your door

[@tarunakhari7144]

👍

[@surfingcipher1059]

tried my hand at the plot of it import numpy as np import matplotlib.pyplot as plt t = np.linspace(0, 50, 1000) # start, finish, n points M_1 = (t+30)*1 M_2 = t * 4 fig, ax = plt.subplots() plt.title('Solar panel') plt.xlabel('time (in days)') plt.ylabel('Energy (in joules)') ax.set_xlim([0, 30]) ax.set_ylim([0, 50]) ax.plot(t, M_1, c='green') ax.plot(t, M_2, c='brown') plt.axvline(x=10, color='purple', linestyle='--') _ = plt.axhline(y=40, color='purple', linestyle='--') plt.show() my brother john, very impressive series.