Question

Show that there are two angles of projection for which the horizontal range (R) is same for the projectile motion.

Answer 1

Dear student
 for same range the angle of projection is θ and 90−θ.Maximum height when particle is thrown at an angle θ ish1=u2sin2θ2g  ...1Maximum height when particle is thrown at an angle 90−θ ish2=u2cos2θ2g..2h1+h2=u2sin2θ2g+u2cos2θ2g=u22gso their sum isindependent of angle

Answer 2

There are 2 angles of projection for which the horizontal range is same for projectile. ... There are two angles of projection for which the horizontalrange is same i.e. θ and 90o - θ.