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Prove It It will be a 2D vector, and parallel to the line defined by the tangent at that point.
To find the tangent, which will be of the form $\displaystyle y = mx + c$, to find $\displaystyle m$, take the derivative, then evaluate the derivative at that point.
$\displaystyle y = x^2$
$\displaystyle \frac{dy}{dx} = 2x$
$\displaystyle \frac{dy}{dx}|_{x = 2} = 4$.
Thus $\displaystyle m = 4$.
We have
$\displaystyle y = 4x + c$
We also have $\displaystyle (x, y) = (2, 4)$ as a point on the tangent.
So $\displaystyle 4 = 4\cdot 2 + c$
$\displaystyle c = -4$.
Thus the tangent is $\displaystyle y = 4x - 4$.
So you will have a vector that is parallel to $\displaystyle y = 4x - 4$ and that passes through $\displaystyle (x, y) = (2, 4)$.
Can you go from here?