Answer:
cos 2Ф = - 161/289 , tan 2Ф = - 240/161
Step-by-step explanation:
* Lets explain how to solve the problem
∵ cos Ф = - 8/17
∵ Ф lies in the 3rd quadrant
- In the 3rd quadrant sin and cos are negative values, but tan is
a positive value
∵ sin²Ф + cos²Ф = 1
∴ sin²Ф + (-8/17)² = 1
∴ sin²Ф + 64/289 = 1
- Subtract 64/289 from both sides
∴ sin²Ф = 225/289 ⇒ take √ for both sides
∴ sin Ф = ± 15/17
∵ Ф lies in the 3rd quadrant
∴ sin Ф = -15/17
∵ cos 2Ф = 2cos²Ф - 1 ⇒ the rule of the double angle
∵ cos Ф = - 8/17
∴ cos 2Ф = 2(-8/17)² - 1 = (128/289) - 1 = - 161/289
* cos 2Ф = - 161/289
∵ tan 2Ф = sin 2Ф/cos 2Ф
∵ sin 2Ф = 2 sin Ф × cos Ф
∵ sin Ф = - 15/17 and cos Ф = - 8/17
∴ sin 2Ф = 2 × (-15/17) × (-8/17) = 240/289
∵ cos 2Ф = - 161/289
∴ tan 2Ф = (240/289)/(-161/289) = - 240/161
* tan 2Ф = - 240/161
The Angles BAF and CEF are equal to one another, because they form pair of Alternate Interior Angles ~
So, the Correct choice is ~
- Yes, They are Alternate interior Angles
The answer is 1.
Im too lazy to show the work, but heres how I checked
-7(1 + 2) = -14 - 7
-7 + (-14) = -14 - 7
-21 = -21
Answer:
10. SAS
11. SAS
12. SAS
13. SSS
14. SSS
15.ASA
Step-by-step explanation:
Answer:
║JF║=75
Step-by-step explanation:
angle JDF = angle JYS ( corresponding angles)
angle JYD = angle JSF ( corresponding angles)
JD/JF=JY/JS=DY/FS
Use JD/JF=JY/JS and substitute:
50/x=42/63, where║JF║
cross multiply
50×63=42×X
3150=42x
divide via by 42
3150/42=42x/42
75=x
x=75
So ║JF║=75
Hope this helps.
