Answer:
1 seconds after being thrown, the stone reaches its max height
Step-by-step explanation:
The parabolic (quadratic) equation is:
Lets expand this in the form 
, so we have:
We can say the values of a,b, and c, now to be:
a = -5
b = 10
c = 40
The number of seconds at which the max would occur is given by the point, x, at:
We know a and b, let's find the seconds, x,
Hence,
1 seconds after being thrown, the stone reach its max height
Answer:
The length is 15 yards
Step-by-step explanation:
Given
Represent the width with W and length with L: So
Required
Determine the length of the rectangle:
Area is calculated as thus:
Substitute 3W - 12 for L and 135 for Area
Reorder:
Divide through by 3
Expand:
or 
or 
But width can't be negative
So:
Recall that:
<em>Hence, the length 15 yards</em>
(0,6) is on the y-axis. (5,-2) is on the 4th quadrant. (-1,10) is on the 2nd quadrant. (-1/4, -6*1/2) is on the 3rd quadrant. (5,0) is on the x axis. (8.7,2.3) is on the 1rst quadrant
