Answer:
√2(√3 - 1)/4
Step-by-step explanation:
To find an exact value for Cos75°, we use the compound angle formula. Since 75° = 45° + 30°, Cos75° = Cos(45° + 30°).
Using Cos(A + B) = CosACosB - SinASinB where A = 45° and B = 30°,
Cos75° = Cos(45° + 30°) = Cos45°Cos30° - Sin45°Sin30°
Now Cos45° = Sin45° = 1/√2 = √2/2, Cos30° = √3/2 and Sin30° = 1/2.
Substituting these values into the above equation, we have
Cos75° = Cos(45° + 30°)
= Cos45°Cos30° - Sin45°Sin30°
= √2/2 × √3/2 - √2/2 × 1/2
= √6/4 -√2/4
= √2(√3 - 1)/4
With continuous data, it is possible to find the midpoint of any two distinct values. For instance, if h = height of tree, then its possible to find the middle height of h = 10 and h = 7 (which in this case is h = 8.5)
On the other hand, discrete data can't be treated the same way (eg: if n = number of people, then there is no midpoint between n = 3 and n = 4).
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With that in mind, we have the following answers
1) Continuous data. Time values are always continuous. Any two distinct time values can be averaged to find the midpoint
2) Continuous data. Like time values, temperatures can be averaged as well.
3) Discrete data. Place locations in a race or competition are finite and we can't have midpoints. We can't have a midpoint between 9th and 10th place for instance.
4) Continuous data. We can find the midpoint and it makes sense to do so when it comes to speeds.
5) Discrete data. This is a finite number and countable. We cannot have 20.5 freshman for instance.
Let:
x = cost of senior citizen ticket
y = cost of student ticket
4x + 5y = 102
7x + 5y = 126
4x + 5y = 102
4x = 102 - 5y
x = (102 - 5y)/4
x = 102/4 - 5y/4
7x + 5y = 126
7(102/4 - 5y/4) + 5y = 126
(714/4 - 35y/4) + 5y = 126
-35y/4 + 5y = 126 - 714/4
note:
-35y/4 = -8.75y
714/4 = 178.5
-8.75y + 5y = 126 - 178.5
-3.75y = -52.5
y = -52.5/-3.75
y = 14
x = 102/4 - 5y/4
x = 102/4 - 5(14)/4
x = 8
x = cost of senior citizen ticket = $8/ea
y = cost of student ticket = $14/ea
7/10 of 80 is 56
4/5 of 80 is 64
3/4 of 80 is 60
5/8 of 80 is 50
1/2 of 80 is 40
1/4 of 80 is 20
1/10 of 80 is 8
1/8 of 80 is 10
to work these out divide the number by the denominator (bottom number) and multiply by the numerator (top number)
