Answer:
13 seconds.
Step-by-step explanation:
Given

Required
Determine a reasonable solution for t
To do this, we equate h to 0.
becomes

Divide through by -4.9

Reorder the expression

Split
or 
This gives:
or 
But time can't be negative, So:

For 6 points, answering 5 questions is a rip-off.
However, I shall answer 7.
haha sike get noob
Answer:
X₁=7 ,X₂ = 5
Step-by-step explanation:
a= 1² b= - 12 c= 35
X =[ ( -b±√b²-4ac ) / 2a]
So, use this formula and get the answer...
Even if you use the middle term formula, you will get the same answer
<h3>Answer:</h3>
x/tan(x) is an even function
sec(x)/x is an odd function
<h3>Explanation:</h3>
<em>x/tan(x)</em>
For f(x) = x/tan(x), consider f(-x).
... f(-x) = -x/tan(-x)
Now, we know that tan(x) is an odd function, so tan(-x) = -tan(x). Using this, we have ...
... f(-x) = -x/(-tan(x)) = x/tan(x) = f(x)
The relation f(-x) = f(x) is characteristic of an even function, one that is symmetrical about the y-axis.
_____
<em>sec(x)/x</em>
For g(x) = sec(x)/x, consider g(-x).
... g(-x) = sec(-x)/(-x)
Now, we know that sec(x) is an even function, so sec(-x) = sec(x). Using this, we have ...
... g(-x) = sec(x)/(-x) = -sec(x)/x = -g(x)
The relation g(-x) = -g(x) is characeristic of an odd function, one that is symmetrical about the origin.