This question is asking "Where does cosine equal

?"
Based on our unit circle values and the domain of the cos^{-1} function, we see that at 30 degrees, or

, cosine is equal to

.
Answer:
7/8 > 2/5
Step-by-step explanation:
7/8 is greater than 2/5.
1. You have the following information:
Sinx=5/13
Cosx=12/13
2. By definiton, you have:
Tanx=(Senx)/(Cosx)
3. When you susbtitute Senx=5/13 and Cosx=12/13 into Tanx=(Senx)/(Cosx), you obtain:
Tanx=(Senx)/(Cosx)
Tanx=(5/13)/(12/13)
Tanx=(5)(13)/(13)(12)
Tanx=65/156
4. Therefore, the answer is;
Tanx=65/156
Let's denote Cindy's age which is unknown with X
We know that Cindy's age is 3 times her age 6 years ago.
6 years ago Cindy's age was the present age (X) - 6 : X-6
The fact that the present age is 3 times her age 6 year ago can be written as:
3*(X-6)
So, finally:
X=3*(X-6)
Steps:
(n-2) * 180 = sum of interior angles
(3-2) * 180 = 180
Bottom Triangle
25 + 51 + x = 180
x = 104
Top Triangle
104 + 34 + x = 180
x = 42
Answer:
42