It must have a medium. It must travel in empty space. Mechanical waves are waves which needs medium of propogation.
Answer:
Explanation:

Subtract both sides by
:

Divide both sides by -2*a:

Add both sides by
:

Subtract both sides by
:

Answer:
The datapoint 9.0 ppm is outlier at the 90% confidence level.
Explanation:
The old data has following values
mean=10.5 mm
standard deviation 0.2 mm
Now the mean of new values is calculated as following

So the value as 9.0 ppm can be considered easily as outlier in this regard.
If he feels like, is interested in it, and is able to grasp it, then why not ? Why not indeed ?
Answer:
Explanation:
Total length of the wire is 29 m.
Let the length of one piece is d and of another piece is 29 - d.
Let d is used to make a square.
And 29 - d is used to make an equilateral triangle.
(a)
Area of square = d²
Area of equilateral triangle = √3(29 - d)²/4
Total area,

Differentiate both sides with respect to d.

For maxima and minima, dA/dt = 0
d = 8.76 m
Differentiate again we get the

(a) So, the area is maximum when the side of square is 29 m
(b) so, the area is minimum when the side of square is 8.76 m