The lines are perpendicular
The function involves the initial speed of the object, and the height
from which it was launched, and whether it was launched upward
or downward. As you can see, your post was corrupted and is
unreadable. But when the object hits the ground, its height is zero.
Set the function equal to zero, solve the quadratic equation that you
have, discard the negative solution, and the positive solution is your
answer.
Answer:
see explanation
Step-by-step explanation:
Using cross- products, that is
=
then ad = bc
Given the ratios
and 
Then equating and using cross- products
If both sides equate then the ratios are equivalent
=
, then
4 × 21 = 6 × 14 ⇒ 84 = 84
Both sides are equal thus the ratios are equivalent