Prove that the maximum horizontal range is 4 times the max height attained by the projectile fired at an inclination so as to have maximum horizontal range
For maximum horizontal range, angle of inclination x = 45 degrees.
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Hence when x = 45,
Maximum range = u2Sin2x / g
= u2 Sin2(45) / g = u2 (1) * (1/g)= u2 /g
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Maximum Height =u2Sin2x / 2g
=u2Sin2(45) / 2g =u2 (1/2) * (1/2g) =u2/ 4g
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Hence Maximum range (u2/g)is 4 times the Maximum height (u2/ 4g)when it attains maximum horizontal range.