Angles helpppp plzzzzz and the plz explain with good details
2 answers:
You might be interested in
The diagram of the triangle is missing, so i have attached it.
Answer:
Surface area = 9.425 sq.units
Step-by-step explanation:
When a triangle having an interior angle as 30°, 60° or 90° is rotated, then a cone is formed.
Thus, we need to find the surface area of the cone.
Surface area of a cone is πr ² + πrL
where;
r = radius of the cone
L = slant height of the cone
I have attached the cone formed as the second image.
Looking at the image of the cone, we need to find the radius and slant height.
From the triangle image, we can use trigonometric ratios;
tan 30 = BC/AB
In surd form, BC/AB = 1/√3
Thus, BC is equivalent to 1 and AB equivalent to √3
Using Pythagoras theorem, we can find AC.
(AC)² = (AB)² + (BC)²
AC = √[(AB)² + (BC)²]
AC =√[(√3)² + (1)²]
AC = √[3 + 1]
AC = √4
AC = 2
So, radius, r corresponds to BC = 1
And slant height L corresponds to AC = 2.
Thus,r = 1 and L = 2
So,
Surface area of cone = π(1)² + π(1)(2) = π + 2π = 9.425 sq.units
Answer:
The expected value of X is 2 with a standard deviation of 1.34.
Step-by-step explanation:
For each speaker, there are only two possible outcomes. Either it is defective, or it is not. The probability of a speaker being defective is independent of other speakers. So we use the binomial probability distribution to solve this question.
Binomial probability distribution
Probability of exactly x sucesses on n repeated trials, with p probability.
The expected value of the binomial distribution is:
The standard deviation of the binomial distribution is:
Stereo speakers are manufactured with a probability of 0.1 of being defective
This means that
Twenty speakers are randomly selected.
This means that
Let the random variable X be defined as the number of defective speakers. Find the expected value and the standard deviation.
The expected value of X is 2 with a standard deviation of 1.34.