Answer:
a) 
b) 
Step-by-step explanation:
Polar coordinates are represented as:
, where 'r' is the length (or magnitude) of the line, and '
' is the angle measured from the positive x-axis.
in our case:

to covert the polar to cartesian:


we can plug in our values:


the Cartesian coordinates are:


(b) to convert (x,y) = (6.06,-3.5)
we'll use the pythagoras theorem to find 'r'



the angle can be found by:




to convert radians to degrees:

writing in polar coordinates:

interior angle of a regular 18-gon.
It is easier to calculate the exterior angle of a regular polygon of n-sides (n-gon) by the relation
exterior angle = 360/n
For a 18-gon, n=18, so exterior angle = 360/18=20 °
The value of each interior angle is therefore the supplement, or
Interior angle = 180-20=160 degrees.
Naming of a 9-gon
A polygon with 9 vertices is called a nonagon (in English) or enneagon (French ennéagone, but the English version is sometimes used)
You had a good start with the correct answer.
Exterior angle of a 15-gon
The exterior angle of a 15-gon can be calculated using the relation given in the first paragraph, namely
Exterior angle = 360/15=24 degrees
Answer:
show in attachment
Step-by-step explanation:
Answer:
Step-by-step explanation:
Given that X the time to complete a standardized exam in the BYU-Idaho Testing Center is approximately normal with a mean of 70 minutes and a standard deviation of 10 minutes.
We have 68 rule as 2/3 of total would lie within 1 std deviation, and 95 rule as nearly 95% lie within 2 std deviations from the mean.
We have std deviation = 10
Hence 2 std deviations from the mean
= Mean ±2 std deviations
=
±20
= 
Below 50, 0.25 or 2.5% would complete the exam.
30/78 simplified is 15/39