Answer:
c)
Step-by-step explanation:
To solve this, remember some properties of trigonometric functions.
Let . Then, by definition of inverse function, . Multiply by -1 to both sides of this equation to get .
Note that because sine is an odd function and cosine is an even function. Then . Take the inverse tangent in both sides to get .
Using the previous equations, we obtain:
You are correct, the answer is b
Area of chalkboard = 4 feet x 6 feet = 24 square feet.
Total cost = 24 square feet x $7.21 per square foot = $173.04
Answer: $173.04
D.
It's D because it's ELAVATION. The plane is going UP.