Answer:
Step-by-step explanation:Since we want to know how much time elapsed since the object was launched until it ht the ground. At the ground, the height is 0.
Therefore the equation h(t) = 80t – 16t2 becomes 0= 80t – 16t2
Solving the equation for t gives 80t =16t2 or 16t=80 or t=5sec
The object hits the ground 5 seconds after it is launched.
To ease your problem, consider "L" as you x-axis
Then the coordinate become:
A(- 4 , 3) and B(1 , 2) [you notice that just the y's changed]
This is a reflection problem.
Reflect point B across the river line "L" to get B', symmetric of B about L.
The coordinates of B'(1 , -1) [remember L is our new x-axis]
JOIN A to B' . AB' intersect L, say in H
We have to find the shortest way such that AH + HB = shortest.
But HB = HB' (symmetry about L) , then I can write instead of
AH + HB →→ AH + HB'. This is the shortest since the shortest distance between 2 points is the straight line and H is the point requiered
Answer:
108
Step-by-step explanation:
65+110+87=252
360(Total angle of quadrilaterals)-252=108
Answer:
9990 years
Step-by-step explanation:
The exponential function with given values filled in can be solved for the unknown using logarithms.
__
Q(t) = 12 = 36e^(-0.00011t)
1/3 = e^(-0.00011t) . . . . . . divide by 36
ln(1/3) = -0.00011t . . . . . . take natural logs
t = ln(1/3)/(-0.00011) . . . . divide by the coefficient of t
t ≈ 9990 . . . years