Standard Equation for trig function: y = A cos (B (x - H))+ K
*Here, we are just dealing with A (amplitude) and B (period)
Period = 2π/ b
8 = 2π/ b
Solve for b: 2π/8 or π/4
Equation: y = 2 cos (π/4 (x))
Answer:

Step-by-step explanation:

All Done!
13.3cm rounded to the nearest 10th
Answer: b = 3
Step-by-step explanation:
1. a^2 + b^2 = c^2
2. 1.6^2 + b^2 = 3.4^2
3. 2.56 + b^2 = 11.56
4. 11.56-2.56 = b^2
5. 9 = b^2
6. 3 = b