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:
9 Days
Step-by-step explanation:
1/2x10=5
1/2x8=4
Logic tells you that 1/2x9=4 1/2
4 1/2 divided by 9= 1/2
So this answer is reasonable!!!
Please mark me brainlist!!! UwU
Answer:
Ben is incorrect
The solutions are x>-3 and x < 3
Step-by-step explanation:
we have

Multiply by -1 both sides

Adds 9 both sides

The solutions are

and
-----> Multiply by -1 both sides ----> 
therefore
The solution is the interval (-3,3)
Ben is incorrect
Answer:
(-2,-2)
Step-by-step explanation:
Answer:
868 m³
Step-by-step explanation:
Volume = Difference of cones
V = ⅓(pi×r²h)
Volume of cone with base Circle O:
h = 8.2+8.2 = 16.4 m
V1 = ⅓(pi×7.6²×16.4)
V1 = 991.97
Volume of cone with base Circle A:
V2 = ⅓(pi×3.8²× 8.2)
V2 = 124 m³
Volume = V1 - V2
991.97 - 124 = 868 m³