Answer:
Part I: cot(15 degrees) = cot(45 - 30)
Part II: Evaluation is below
Step-by-step explanation:
<em>Everything is done in degrees</em>
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Two angles that differ by 15 degrees that is easy to evaluate is 30 degrees and 45 degrees. The cot(15 degrees) = cot(45 - 30) = 1/tan(45-30) = (1+tan45tan30)/(tan30 - tan45) = (1+ sqrt(3))/(sqrt(3) - 1)
We rationalize this by multiplying 1+ sqrt(3) in the top and bottom, getting:
(4 + 2sqrt(3))/2 = 2 + sqrt(3)
I hope this helps! :)
Answer:

Step-by-step explanation:


Use <em>FOIL</em> method.


Answer:
Step-by-step explanation:
radius=4 as it is tangent to x-axis.
y co-ordinate of center is 4 so radius=4
eq. of circle is (x-2)²+(y-4)²=4²
or x²-4x+4+y²-8y+16=16
or x²+y²-4x-8y+4=0
Answer:
vertex and x= -b/2a = 0
second point, when x=1, y=3
third point the mirror of the second point over the vertex
Step-by-step explanation:
Do as described
Answer:
a) The probability that 71 of 150 will prefer boy child is 71/150 or 0.47
b) The result contradicts the poll actual percentage is 47.33% which is 3.33% more than the poll predicted
Step-by-step explanation:
If 71 out of 150 prefer boy child
The probability that the 71 will prefer boy child is
= 71/150
The actual percentage is
(71/150)*100%
= 47.33%
This contradicts the poll as this is more than the poll predicted. That means Less than 71 of 150 actually preferred boy child.