# Name that curve

Seriously. It’s about time we started talking math on an ongoing basis. This seems as good a place as any to open the floor.

What’s the ol’ saying… if it walks like a cube, and quacks like a cube, it’s a duck.

It's a plot of

`y = x ^ 3`

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No, it’s a “squiggle” 1 Like

Here’s another easy one…

What is the relation that is plotted (in equation form)?

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`r ^ 2 = (x - h) ^ 2 + (y - k) ^ 2` where `(h,k)` is the centre point of your circle and `r` it’s radius.

`g = c` where `g` is the graph and `c` is a circle

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Given all our recent concerns, PI day flew right past us.

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It’ll come back around

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What will the curve tendency be in this…

``````>>> two_day_change = [23, 39, 56, 74]
>>> x = two_day_change
>>> [b / a for (a, b) in zip(x[:-1], x[1:])]
[1.6956521739130435, 1.435897435897436, 1.3214285714285714]
>>>
``````

???
What does this mean?

It’s a little mathematical aside. 1 Like

oh ok ty for telling!

I agree; looks like the cube function … y = x^3
What’s the code to make that graph in Matplotlib in Python?

Ok, so the sequence started `x = [23, 39, 56, 74]`
which is a quadratic sequence since the differences between the terms increase by a constant amount …

x = [23, 39, 56, 74]
print( [ x[i] - x[i - 1] for i in range(1,4) ] )

# [16, 17, 18]

I assume that curve tendency means the limit of this sequence ( meaning what we’d go to if we could go to an index of infinity )

`b/a` was the ratio of a term to the previous term of the sequence
So …

this ratio goes to 1 as we’d go infinitely far out in the sequence.

`x[n] = 0.5*n**2 + 15.5*n + 23`
Full disclosure: I used to be a math teacher. 