Given:

To find:
The exact value of cos 15°.
Solution:

Using half-angle identity:


Using the trigonometric identity: 

Let us first solve the fraction in the numerator.

Using fraction rule: 

Apply radical rule: ![\sqrt[n]{\frac{a}{b}}=\frac{\sqrt[n]{a}}{\sqrt[n]{b}}](https://tex.z-dn.net/?f=%5Csqrt%5Bn%5D%7B%5Cfrac%7Ba%7D%7Bb%7D%7D%3D%5Cfrac%7B%5Csqrt%5Bn%5D%7Ba%7D%7D%7B%5Csqrt%5Bn%5D%7Bb%7D%7D)

Using
:


Answer:
68
Step-by-step explanation:
1) Find the interior angle using relations of angles in straight line I.e ( sum of angles in a straight line is 180 ) and we know the sum of all the interior angle of quadrilateral is 360 degree .
2) Solve further for x.
Answer:
x - intercepts: (-5,0), (5,0), (7,0)
I'm not sure if you would count these, but x and y also have the intercept of (0,0).
If you want to cheat, paste the formula in Wolfram Alpha. However, this one is not that difficult. From the fact that x and y are squared you can infer that this is a circle. The 9 reveals that the radius r^2 is 9, so radius is 3.
The (x-2) tells us that the circle is shifted to the right by 2. Likewise, y+1 shifts it down by one. So the center is at (2,-1). If the equation would be x^2 + y^2 = 9, you'd have a circle exactly on the origin.
Hopefully this helps you break down the equation and pick the right picture!
Answer: The correct answer is H.
Step-by-step explanation: The correct order of the weights from largest to smallest is shown in choice H. The correct order is 2.25, 2.234, 2.205.