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:
2πr or πd
Step-by-step explanation:
Where
π= pi
r= radius of the circle
d= diameter of the circle
Answer:
x= -9
Step-by-step explanation:
7(x+2)=-49
divide both sides by 7
(x+2)=-7
subtract 2 from both dies
x= -9
The answer is 1;3 because if you simplified 2;6 you get 1;3 so the answer to that is
a: 1;3