Answer:
See Explanation
Step-by-step explanation:
<em>Question like this are better answered if there are list of options; However, I'll simplify as far as the expression can be simplified</em>
Given

Required
Simplify

Represent
with a
Represent
with b
The expression becomes

Factorize



Recall that

The expression
becomes

..............................................................................................................................
In trigonometry

Subtract
from both sides


..............................................................................................................................
Substitute 1 for
in 

Open Bracket
------------------This is an equivalence

Solving further;
................................................................................................................................
In trigonometry


Substitute the expressions for secx and tanx
................................................................................................................................
becomes

Open bracket


Add Fraction
------------------------ This is another equivalence
................................................................................................................................
In trigonometry

Make
the subject of formula

................................................................................................................................
Substitute the expressions for
for 

Open bracket

---------------------- This is another equivalence
Make hours to seconds to match meters
19.6*3600=70560 seconds
And is dropped from a height of 15.4 meters then the velocity will be
15.4m/70560s = 0.0002182539m/s
Answer:
68
Step-by-step explanation:
identity property=something times one
Answer:45
Step-by-step explanation: