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$$
Ф β △ τ αφωψπΩΓεγµσ←↑→θηδ≤≥
$$

$$ x^2 $$

$$ ρ $$

$$

$$

$$sum_{i=0}Nint_{a}{b}g(t,i)text{d}t$$

$ J left ( thetaright )= frac{1}{2m}sum_{i=1}^{m}left ( h_{theta }left ( x^{left ( i right )} right )-y^{left ( i right )} right )^{2} $