Answer:
cos (a+b)= cos a cos b - sin a sin b
Step-by-step explanation:
I had to answer this question too, but I don't know the explanation. I just saw it in this Khan Academy video. https://www.khanacademy.org/math/precalculus/x9e81a4f98389efdf:trig/x9e81a4f98389efdf:angle-addition/v/cosine-addition-identity-example
Answer:
50.90 cm
Step-by-step explanation:
The computation of the circumference of this circle is shown below:
As we know that
The circumference of this circle is
= 2πr
where
π is 3.142
r = diameter ÷ 2
= 16.8 ÷ 2
= 8.1 cm
So, the circumference of the circle is
= 2 × 3.142 × 8.1 cm
= 50.90 cm
9 classes = 225
1 class = 25
125 ÷ 25 = 5
the answer is B
The tree diagram for the probability is shown below
P(Clay|Positive) is read 'Probability of Clay given the result is Positive'.
This is a case of conditional probability.
The formula for conditional probability is given as
P(Clay|Positive) = P(Clay∩Positive) ÷ P(Positive)
P(Clay∩Positive) = 0.21×0.48 = 0.1008
P(Positive) = P(Rock∩Positive) + P(Clay∩Positive) + P(Sand∩Positive)
P(Positive) = (0.53×0.53) + (0.21×0.48) + (0.26×0.75)
P(Positive) = 0.2809 + 0.1008 + 0.195
P(Positive) = 0.5767
Hence,
P(Clay|Positive) = 0.1008÷0.5767 = 0.175 (rounded to 3 decimal place)