A projectile is launched with an initial speed of [v0] m/s a…

A projectile is launched with an initial speed of  m/s at an angle of ° above the horizontal. The projectile lands on a hillside  s later. Neglect air friction. (Assume that the +x-axis is to the right and the +y-axis is up along the page.) What is the angle of the projectile’s velocity at the highest point of its trajectory, relative to the horizontal (the +x-axis)?