Answer:
D. 
Step-by-step explanation:
For each of these problems, remember SOH-CAH-TOA.
Sine = opposite/hypotenuse
Cosine = adjacent/hypotenuse
Tangent = opposite/adjacent
5) Here we are looking for the cosine of the 30 degree angle. Cosine uses the adjacent side to the angle over the hypotenuse. Therefore, cos(30) = 43/50.
6) We have an unknown side length, of which is adjacent to 22 degrees, and the length of the hypotenuse. Since we know the adjacent side and the hypotenuse, we should use Cosine. Therefore, our equation to find the missing side length is cos(22) = x / 15.
7) When finding an angle, we always use the inverse of the trigonometry function we originally used. Therefore, if sin(A) = 12/15, then the inverse of that would be sin^-1 (12/15) = A.
8) We are again using an inverse trigonometry function here. We know the hypotenuse, as well as the side adjacent to the angle. Therefore, we should use the inverse cosine function. Using the inverse cosine function gives us cos^-1 (9/13) = 46 degrees.
Hope this helps!
Answer:
The unit vector u is (-5/√29) i - (2/√29) j
Step-by-step explanation:
* Lets revise the meaning of unit vector
- The unit vector is the vector ÷ the magnitude of the vector
- If the vector w = xi + yj
- Its magnitude IwI = √(x² + y²) ⇒ the length of the vector w
- The unit vector u in the direction of w is u = w/IwI
- The unit vector u = (xi + yj)/√(x² + y²)
- The unit vector u = [x/√(x² + y²)] i + [y/√(x² + y²)] j
* Now lets solve the problem
∵ v = -5i - 2j
∴ IvI = √[(-5)² +(-2)²] = √[25 + 4] = √29
- The unit vector u = v/IvI
∴ u = (-5i - 2j)/√29 ⇒ spilt the terms
∴ u = (-5/√29) i - (2/√29) j
* The unit vector u is (-5/√29) i - (2/√29) j
Answer:
250 minutes with the flat rate of $29.
x would be the number of minutes called.
Tracy would be charged by $0.35 per minute.
