Two objects move through the air. The movement of the first can be described by the equation $(4t, 6+3t)$, the second by $(20-70(t-2)\cos u, 70(t-2)\sin u)$, where the parameter $t$ represents time and $u$ is the angle between the ground and the second objects direction.
How do you solve this? I tried cancelling $u$ by $\sin^2 u+\cos^2 u = 1$, but I dont think I get a reasonable answer...