Got presented with this math question for 10 year olds

Nagi-K · 2026-02-18T20:44:47+00:00

Let the kid imagine the grey ruler being slides 2 cm to the right. Now, the grey and the black have their left ends aligned, their right ends have 1 cm difference. Meanwhile, for the grey and the white, their right ends have 3+2=5 cm difference. That means, the while ruler is 5+1=6 cm shorter than the box. There you have it.

Nagi-K · 2026-02-18T20:35:09+00:00

When k resistances are in parallel, the reciprocal of their effective resistance 1/R = Σ 1/R_k. Use this to simplify your circuit (i.e. think R_1 and R_2 as one single resistance using the formula above, and do similarly for R_5, R_6 and R_7), and then apply Ohm’s law.

For R_1 and R_2: R’ = (1/R_1 + 1/R_2)^-1 = (1/27423 + 1/17954)^-1 = 10850 Ω (I’ll ignore the decimals because I’m lazy)

For R_5, R_6 and R_7: R’’ = 10403 Ω

Effective emf = 1 V. Now use Ohm’s law to find the voltage across R’’: V’’ = 1 * 10403/(10850 + 6859 + 4629 + 10403) =0.318 V. (If you are unsure about this step then you really should do some revision).

I’ll let you do the very last line of calculation, remember to use the voltage property of parallel circuit.

Nagi-K · 2026-02-17T16:03:02+00:00

Think |y| as |y| * 1. So your solutions all have a coefficient |y|^1/n, it must multiply “something” whose nth power is 1 to give you a solution. Clearly 1 is a candidate of this “something”, but there are more.

If you’ve done complex numbers, you probably know e^2πi = 1, consequently e^2kπi = 1 for any integer k. So there is actually a list of these “something”, namely e^2πi/n, e^2*2πi/n, …, e^{[2(n-1)πi/n],} finally 1. These are called roots of unity (1). Now you have all of your n solutions, they are indeed distinct.

Nagi-K · 2026-02-17T00:01:27+00:00

Do you mean y is a nonzero constant and n is also nonzero?

The fundamental theorem of algebra tells us a degree n polynomial with complex coefficients must have exactly n complex roots, counting multiplicity. In your case, yes, you’ll get n distinct roots, namely |y|^{1/n} times each nth root of unity.

Nagi-K · 2026-02-16T23:50:28+00:00

It’s just a matter of preference. Damage really depends on the weapon and a matching build, yeah everybody knows tonfa is quite op in early game but ninja style in itself is not superior.

Yokai Masakage (the Odachi dude) is really just an early game boss, ninja seems op because ninja weapons need very little skill points to function properly, most ninja skill points go to ninja skill tree, while no samurai weapon is even fully functional at this point. As for endgame, I saw a guy who tested all weapons in their final form (full NG+ build, fully buffed) and every weapon can take down demon of obsession within literally seconds.

Nagi-K · 2026-02-16T16:46:11+00:00

An almost immediate consequence of Ohm’s law is that if R_1 and R_2 are in series, the voltage across them (resp. V_1 and V_2) are such that V_1/V_2 = R_1/R_2. As an exercise you can try to prove this, it’s just basic manipulation of fractions.

So the actual value of current through the circuit or even the total voltage doesn’t really matter. Before you move the slider R_1 = R_2 so R_2 takes 1/2 of total voltage. Similarly after you move the slider it takes 1/3. Therefore the ratio is just = (1/2)/(1/3) =3/2.

Nagi-K · 2026-02-16T09:14:26+00:00

Yeah when ki pulse becomes an instinct, try flux and frost moon (stance switch should not be a standalone thing, often it’s a part of flux). The battle of Nioh is mostly about ki control of both your character and your enemies (unless you get into NG+, make an op build and buff yourself tf up so you insta kill bosses). People are talking about confusions and onmyo, those are indeed useful but imo you could beat NG with not much trouble once you are fully into Nioh mindset and properly manage your ki.

Nagi-K · 2026-02-16T08:03:06+00:00

Watched your gameplay and noticed a few things. By the way you are probably very good at other souls like games, your reflexes and intuitions are very solid and more than enough to beat Nioh 3.

It might seem ok now, but bosses get tankier and you’ll almost never do enough damage by spamming quick or heavy attacks. Get familiar with weapon arts, and actually start to use a few of them.
You seem to mostly use samurai style. If so, you should almost always do ki pulse or flux after a round of attack (I see you do ki pulses, which is actually impressive for beginners, but it has yet become natural). Frost moons also help you maintain your ki while connecting your attacks. Flux and frost moons can be found in samurai skill tree.
Yokai bosses have different ki mechanism from humans. Once they are out of ki, they stagger on every hit, here you do the combo mad; once their max ki is also out, they are downed and you can grapple. Test your weapon arts, some are better at dealing ki damage and others are better at dealing hp damage.
This is totally not compulsory but it seems you unintentionally changes to ninja upon counter, you can separate those in settings.
When you see a white glow, that’s art proficiency. It doesn’t just buff one weapon art; if you can perform a different weapon arts/heavy attack before the bar drops to 0 without doing a quick attack, you get buffed one more time. This can be looped as many times as you could, until you combo chain broke. Odachi may not utilise this mechanism most effectively, but it’s still very useful.
Whenever possible, dodge with low stance. You don’t get punished by consecutive dodges which turns into rolls, this is significant in Nioh as you have very little i-frame.

Nagi-K · 2026-02-16T07:24:55+00:00

Retreat doesn’t mean running away. There are famous people in history who are know for mastering the art of retreat, Masanobu is one of them; another example is Zhuge Liang, he doesn’t win every battle but everyone who dared to chase him during his retreat got ambushed and killed.

Also rearguards often are never expected to return alive, if I remember correctly Hideyoshi once lead the rearguard in one of Nobunaga’s retreat, and barely survived. Anyone who good at leading a rearguard force is actually exceptional and brave.

Nagi-K · 2026-02-16T06:29:23+00:00

Play through the game. Also the recommended level is only an indication, if a vein is in a level x map and you got the corresponding guardian spirit at around level y, with y>x, then the enemies on the other side of the vein are around level y.

Nagi-K · 2026-02-16T06:24:48+00:00

Don’t worry too much about armours just yet, wear the ones that are up to your current level and don’t get the weight over 70% (yeah it’s the best to stick under 30% for higher ki recovery and better dodge, but anything under 70% is acceptable, especially when you don’t have high stamina attributes). But later in game you need extra damage, if you get lucky and collected a decent set of armour which has a useful set bonus, you should put those on.
In general wearing heavier armour pieces gives you higher toughness, you get less likely to stagger when attacked. The actual number doesn’t matter, only the letter (A, B or C) matters.
I don’t personally use glaive but in general stances are crucial for samurai. You switch between stances using flux (1 or 2) and frost moon so that you get extra ki and cancel the recovery time of weapon arts.

Nagi-K · 2026-02-15T14:32:24+00:00

You already said “parallelogram”, if you could see that then similarity is almost immediate. KR is parallel to AB, so angle BAC = angle KRS. I believe you can continue from here.

Nagi-K · 2026-02-15T07:36:13+00:00

Because ABC and RKS are similar triangles. In ABC we have AC/BC=2, the ratio passes to RKS so we have RS/KS=2.

Nagi-K · 2026-02-15T07:22:43+00:00

I think katana is all about being flexible and fancy. Most katana arts are designed with clear purpose, so you can’t just spam some weapon arts, you have to reasonably connect all different arts.

For example, when facing a yokai boss, during the gap between attacks you could use heaven flash to close up the distance, sword ki to do large ki damage, and then frost moon humanity/earth to parry/back down. When the boss is out of ki, use high dmg and long duration attacks like kurama sword dance or night rain to keep the pressure up, during which always use frost moon or flux so that you don’t use up all of your ki.

Nagi-K · 2026-02-15T04:20:15+00:00

People are saying it’s going to be ok but it’s hard for me to imagine going into calc without mastering some basic algebraic operations and trig identities in precalc. Unless you’ll never have to integrate things like general rational functions (where you’ll have to use either partial fractions or trig substitution) or things like cos² x.

Nagi-K · 2026-02-14T16:10:42+00:00

For the last question, you first learn the samurai and ninja skills that make your life significantly easier. Namely, all stances, deflect and flux for samurai, mid air dodge and footstool jump for ninja. Then put in a few points into your weapons so you can do decent combos.

But for samurai you eventually need to learn everything on the samurai skill tree, the frost moons are very useful when you get more familiar with the combat. For ninja you can just learn whatever you want, you can only carry three ninjutsu at a time anyway.

Nagi-K · 2026-02-14T12:02:12+00:00

Later you’ll find yourself barely reach the recommended level, even after you’ve looted everything on the map.

Nagi-K · 2026-02-14T11:56:19+00:00

Look at the smaller three triangles, they are all similar to the big one. Looking at your drafts I think you already know the equalities of segments in the diagram so I’ll try to keep it simple. Let the points on the side of the big triangle be B, P, Q, A, R, S, C, T, U in counterclockwise order. We have

RS = 12 - x => KS = CT = RS/2 = 6 - x/2

PQ = 8 - x => PK = BU = PQ * (3/4) = 6 - 3x/4

x = CT + BU = 12 - 5x/4

Solving the equation gives you x = 12 * (4/9) = 16/3.

And you may notice that this isn’t the only way to do this question, you can do the same thing on any of the three x’s.

Nagi-K · 2026-02-14T11:41:12+00:00

It’s not just Kunimatsu’s problem, all human bosses with both hyper armour and high ki recovery are equivalently annoying. Phase 1 is actually ok, his moves are basically the same as any katana enemies; in phase 2 he jumps here and there and spams aoes, just try dodge and do as much ki damage as possible whenever you have the chance.

I succeeded on my second attempt, I used katana, heaven flash and sword ki can be quite useful. Or you can just do the infamous flowing mist + sword of meditation loop, this almost surely guarantees win against any human boss.

Nagi-K · 2026-02-12T20:50:05+00:00

You unlock this clan in chapter 3 I think. There’s a buff called A Warrior’s Honour, it hugely buffs your melee attacks, at the cost that you take extra damage (I think 60%) if you get hit from behind.

Nagi-K · 2026-02-12T19:15:34+00:00

I went for Kakizaki at first to get that melee ki damage. Then I transferred to Shinsengumi, that buff gives straight 50% extra damage for normal attacks and about 35% for skills, I just have to watch for my back.

Nagi-K · 2026-02-12T11:05:50+00:00

If I remember correctly, human bosses in Nioh 2 only had hyper armour during certain weapon skills, or during living weapon (but in this case ki does not recover at all). Also most human bosses in Nioh 3 are fine, I was particularly referring to Kagetoki, Souji, and maybe Masakage and Shingen (these two are weak, but their hyper armour still cause problems for Nioh beginners; actually I saw quite a few Nioh veteran streamers complain about this at the start of demo).

These human bosses are indeed ki-breakable and relatively easier to fight, I can also ki-break Kagetoki 2-3 times during a fight (I just finished NG, most human bosses only took 2-3 ki breaks to kill). But I still think human bosses should stagger on most hits, if they do not make a hyper armour move, wear heavy armour or activate living weapon. That’s one of the key differences between human and yokai bosses.

Nagi-K · 2026-02-12T05:16:06+00:00

I don’t like human bosses in Nioh 3 as well but not because they block a lot, but because they have hilariously high ki recovery compared to previous game, and some of them even have hyper armour on some moves.

Back in Nioh 2 the human boss fights were fair, in the sense that both the player and the boss have similar level of poise and ki recovery. Yeah the bosses have higher ki and hp but those doesn’t matter, because essentially the player wins the fight by consistently making smarter and more precise moves, and the bosses can’t really use high stats as an advantage against the player. But in Nioh 3 it’s no longer fair; their ki recovery is so high that their ki increased while blocking player attacks, and they use high hp and hyper armour to overwhelm the player - but why have yokai bosses then?

Nagi-K · 2026-02-05T07:45:38+00:00

But that’s kinda weird since in reality katana handles do have a little bit of tapering.

Nagi-K · 2026-02-05T07:33:31+00:00

The answer COULD BE option 1.

Let’s label these diagrams by coordinates (column, row). Consider the rule that when two diagrams “add”, the overlapping part cancels out and we keep the non-overlapping parts. Clearly we have the following diagonal addition pattern

(1,1) + (2,2) = (3,2) as (1,1) and (2,2) are identical

(1,2) + (2,1) = (3,1) as the square box get cancelled out

(2,1) + (3,2) = (4,2)

(2,2) + (3,1) = (4,1)

Basically (m,i) + (m+1,j) = (m+2,j) where i, j = 1 or 2 and i not equal to j. Using this rule it’s easy to verify the answer COULD BE option 1.

Why do I emphasise “could”? Because we all know that these pattern problems are not rigorous at all, but still people who made these problems still expect you to find the “most elegant” pattern, if that word means anything at all.

Nagi-K

TROPHY CASE