Answer:
12.63 km/hr
Step-by-step explanation:
Given the distance=240km
At 12 km/hr it will take =240/12 =20
time for Express train = 20-1=19
speed=240/19=12.63...km/hr
The <em>trigonometric</em> function that represents the curve seen in the picture is f(x) = 4.5 · sin (π · x / 2 - π) - 6.5.
<h3>How to derive a sinusoidal expression</h3>
In this problem we need to find a <em>sinusoidal</em> expression that models the curve seen in the picture. The most typical <em>sinusoidal</em> model is described below:
f(x) = a · sin (b · x + c) + d (1)
Where:
- a - Amplitude
- b - Angular frequency
- c - Angular phase
- d - Vertical midpoint
Now we proceed to find the value of each variable:
Amplitude
a = - 2 - (-6.5)
a = 4.5
Angular frequency
b = 2π / T, where T is the period.
0.25 · T = 4 - 3
T = 4
b = 2π / 4
b = π / 2
Midpoint
d = - 6.5
Angular phase
- 2 = 4.5 · sin (π · 4/2 + c) - 6.5
4.5 = 4.5 · sin (π · 4/2 + c)
1 = sin (2π + c)
π = 2π + c
c = - π
The <em>trigonometric</em> function that represents the curve seen in the picture is f(x) = 4.5 · sin (π · x / 2 - π) - 6.5.
To learn more on trigonometric functions: brainly.com/question/15706158
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Answer:
Step-by-step explanation:
Yo when you get these kind of questions you can use desmos calculator, for the future.
Answer:
d
Step-by-step explanation:
d
