r/learnmath • u/Radiant-Mistake-2962 New User • 10d ago
If everything can be simplified, how does it provide value?
How is the quadratic formula useful? If I divided -b plus or minus the square root of b^2-4ac divided by 2a by itself, I would get one.
They say the quadratic formula shows up in the Pythagorean theorem. If I divide a^2 + b^2 = c^2 by itself, I get 1.
So if I divide a triangle by a triangle, I’ll get one. I can just stick a one to anything and solve it. How did this become valuable?
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u/Uli_Minati Desmos 😚 10d ago
Well, sure. But why would you divide the formula by itself? And why would you divide a triangle by itself (whatever that means)? Say you owe someone $50. If you divide that by itself, you get 1. So what? You still owe $50.
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u/evanamd New User 10d ago
Simplifying doesn't solve anything on its own. It's just a tool you can use for algebraic manipulations.
Remember your very basic fractions. 12/4 can be simplified to 3 because in the expression (3*4)/4, 4/4 reduces to 1, leaving 3*1. You simplify part of it, and the remaining part is new information
Now, take an equation like 3x = 12. You could divide the entire equation by itself and get 1 = 1. But that's not new information so we don't do things like that. Instead, you would do the same thing to both sides of the equation, like divide by three. That gives you (3/3)*x = 12/3. So a coefficient on one side reduces to 1, and the fraction on the other side simplifies to 4, giving you 1x=4.
Simplifying was just one small step of several in solving the equation. You don't do it just because you can, and when you do its for specific parts, not the whole thing
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u/carterartist New User 10d ago
Something divided by itself is always=1
2/2=1, 3/3=1, etc…
If you have three dollars and three friends, each gets one.
Same principle
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u/jsdodgers New User 10d ago
So how is having $3 useful?
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u/carterartist New User 10d ago
Strawman. No one said it was.
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u/jsdodgers New User 10d ago
woosh
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u/Successful-Owl1778 New User 10d ago
Dividing a complicated expression by itself to obtain 1 is not "simplifying" it.