Question

a)
linear function, of the form $f(x) = mx + b$
cubic function, of the form $f(x) = ax^3 + bx^2 + cx + d$
exponential function, of the form $f(x) = a \cdot b^x + c$
reciprocal function, of the form $f(x) = \frac{a}{x}$
root function, of the form $f(x) = a \sqrt{bx} + c$
b)
linear function, of the form $f(x) = mx + b$
cubic function, of the form $f(x) = ax^3 + bx^2 + cx + d$
exponential function, of the form $f(x) = a \cdot b^x + c$
reciprocal function, of the form $f(x) = \frac{a}{x}$
root function, of the form $f(x) = a \sqrt{bx} + c$

Explanation:

For the first (top) question: The selected cubic function has a curved, S-like or oscillating trend typical of 3rd-degree polynomials.
For the second (bottom) scatter plot: The data shows a curve that decreases rapidly at first, then levels off approaching a horizontal asymptote, which matches the shape of an exponential decay function of the form $f(x) = a \cdot b^x + c$ (where $0 < b < 1$).

Answer:

Top question: cubic function, of the form $f(x) = ax^3 + bx^2 + cx + d$
Bottom question: exponential function, of the form $f(x) = a \cdot b^x + c$