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:10 gallons are needed to paint 15,000 square feet of wall.
Step-by-step explanation:
3,000/2=1,500
15,000/1,500=10 gallons
The best prediction for the number of customers is 5450.
To find this value, you just need to plug in 20 for x into the expression. Then, evaluate it using the order of operations.
8(20)^2 + 100(20) + 250
8(400) + 100(20) + 250
3200 + 2000 + 250
5450
56.6 - 3.2 = 53.4
53.4 / 2 = 26.7
26.7 - 6 = 20.7ml
For the final answer she has 20.7ml of solution left.
Please mark as brainliest if you can