Choose a number line to model the following situation. After walking 5 steps forward, Julie walked 5 steps backward.
2 answers:
You might be interested in
Answer:
<u>Step-by-step explanation:</u>
y = A cos (Bx - C) + D
- A (amplitude) = max - D
- B = Period/2π ---> Period is the distance from max to next max
- C = B · Phase Shift ---> Phase shift is distance from y-axis to max
- D (vertical shift) = (max + min)/2
D = (max + min)/2 = (3 - 11)/3 = -4
A = max - D = 3 - (-4) = 7
Period = 9π/4 - π/4 = 8π/4 = 2π
B = Period/2π = 2π/2π = 1
Phase Shift = π/4 - 0 = π/4
C = B · Phase Shift = 1 · π/4 = π/4
Equation:
y = 7 cos (1·x - π/4) + (-4)
9514 1404 393
Answer:
5. 88.0°
6. 13.0°
7. 52.4°
8. 117.8°
Step-by-step explanation:
For angle A between sides b and c, the law of cosines formula can be solved to find the angle as ...
A = arccos((b² +c² -a²)/(2bc))
When calculations are repetitive, I find a spreadsheet useful. It doesn't mind doing the same thing over and over, and it usually makes fewer mistakes.
Here, the side opposite x° is put in column 'a', so angle A is the value of x. The order of the other two sides is irrelevant.
__
<em>Additional comment</em>
The spreadsheet ACOS function returns the angle in radians. The DEGREES function must be used to convert it to degrees. The formula for the first problem is shown here:
=degrees(ACOS((C3^2+D3^2-B3^2)/(2*C3*D3)))
As you can probably tell from the formula, side 'a' is listed in column B of the spreadsheet.
The spreadsheet rounds the results. This means the angle total is sometimes 179.9 and sometimes 180.1 when we expect the sum of angles to be 180.0.
