Answer:
32
Step-by-step explanation:
Suppose Alvin is x years old. Then Elga is x+15 years old.
x+x+15=49
2x=34
x=17
17+15=32
The cheapest service would be the year in which the mean was the lowest. In Year 4, the mean was the lowest.
The most consistent service would be the year in which the range was the lowest. In Year 3, the range was the lowest.
8. Answer: (C) 101.3
<u>Step-by-step explanation:</u>
Use the Law of Cosines:
c² = a² + b² - 2ab·cos C
28.2² = 16.9² + 19.5² - 2(16.9)(19.5)·cos C
795.24 = 285.61 + 380.25 - 659.1 cos C
795.24 = 665.76 - 659.1 cos C
129.38 = - 659.1 cos C
-0.196 = cos C
cos⁻¹ (-0.196) = cos⁻¹ (cos C)
101.3 = C
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10. Answer: (A) 27.9
<u>Step-by-step explanation:</u>
Use the Law of Cosines:
c² = a² + b² - 2ab·cos C
c² = 25² + 18² - 2(25)(18)·cos 79
c² = 625 + 324 - 900 cos 79
c² = 949 - 171.7
c² = 777.3
√c² = √777.3
c = 27.9
Answer:
"Haruto is correct because the angle is coterminal with 3pi/4 and the reference angle is pi/4."
Step-by-step explanation:
Coterminal angle:
Coterminal Angles are angles who share the same initial side and terminal sides. Finding coterminal angles is as simple as adding or subtracting 360° or 2π to each angle, depending on whether the given angle is in degrees or radians.
Finding if 3pi/4 is coterminal with 19pi/4:
19pi/4
= 16pi/4 + 3pi/4
= 4pi + 3pi/4
= 2(2pi) + 3pi/4
= 2(360°) + 3pi/4
= 3pi/4
Hence they are coterminal.
Reference angle:
The smallest angle that the terminal side makes with x-axis.
3pi/4 falls in second quadrant.
In 2nd quadrant, reference angle is given as = pi - 3pi/4
reference angle = pi/4.