\(y=4 t-2 t^2\)

\(x=3 t\)

\(V=V_{x \hat{i}}+V_{y \hat{j}}\)

\(V_x=\frac{d x}{d t}, V_y=\frac{d y}{d t}\)

\(V_x=3, V_y=4-4 t\)

for \(t=0, V_y=4\)

\(\tan \theta=\frac{V_y}{V_x}=\frac{4}{3}\)

\(\theta=53^{\circ}\) with horizontal

With vertical

\(\theta=37^{\circ}\)