Mathematical Induction - Divisibility Tests (1) | ExamSolutions

Here I look at using proof by mathematical induction for divisibility tests.

[chaudharymuqarrabhussain]

Last hour prep (literally had been crying) and this man is here to give you the best in a few minutes

[Toxid]

I've been working with this thing for hours, and now with the help of your video I could finally solve it

[TimerUchiha]

You've just saved a life.
Thank you for this really understandable video :)

[bellamaddison]

Wow thank you so much
I've been finding it so difficult to solve questions like this
You really help me a lot
Keep it up!
Thank you so so much!!!

[structuralcraft]

If I had found this video earlier in my study, I could save 30mins.

[suzukiliciously]

How does he get to the conclusion that it is 8(3^2k) - my question goes as to how it is 8, in particular, and what happens to the - 3^2k? Cheers guys, I'm a total rookie who just need to understand how the algebraic expression is simplified?!?

[minutesquickvideos]

Can you please explain why we don't add the n= k+1 to n=k? I am a little confused on the part where you did f(k+1)-f(k) and why you did that.
I understand the rest but if you can just explain that part then all the gaps will be filled :) .

Thanks

[alvinjoffy]

Thankyou very much for making me understand this concept
Nice teaching

[billywalshpatricianpresent]

great method. thanks. would this method work for something such as prove 2^(3n) - 3^n is divisible by 5 for all natural numbers

[Kebab_with_extra_garlic_mayo]

why did you add f(k) I do the same method but I dont  add f(k) and i make F(k+1) = 8A and then i Factor

[NaomiManda-umrj]

Where does that 8 come from cause 3² is 9

[ExamSolutions_Maths]

Thank you, that would be really appreciated.

[joshuafeuer]

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[sophia]

Can anyone tell me how 3^2.3^2k - 3^2k = 8(3^2k)???
Please guide me about that if anyone is reading my comment, I'm stuck here 🥺🥺

[star-eoni]

i just remember i used to watch your vid for my high school math and addmath and i got AandA+ for both sybject . and now im watching you for my math foundation 😢😢🥺🥺

[ELLIPTICALWR]

how would you use proof by induction to prove a function is not divisible by a real number, like n^3 +2 for example is not divisible by 8

[amythestgemini]

is this pre-algebrq, algebra or calculus?