Questions: The figure below shows y=3 sin(5x) and y=3 sin(10x).
Which graph is y=3 sin(5x) ?
Choose one △
Identify the values labeled a to e in the figure.
NOTE: Enter exact values or round to three decimal places.
a= □ d= □
b= □ e= □
c= □
Transcript text: The figure below shows $y=3 \sin (5 x)$ and $y=3 \sin (10 x)$.
Which graph is $y=3 \sin (5 x)$ ?
Choose one $\nabla$
Identify the values labeled $a$ to $e$ in the figure.
NOTE: Enter exact values or round to three decimal places.
$a=$ $\square$ $d=$ $\square$
$b=$ $\square$ $e=$ $\square$
$c=$ $\square$
Solution
Solution Steps
Step 1: Identify the graph of y = 3sin(5x)
The graph of y = 3sin(5x) has a period of 2π/5. The graph of y = 3sin(10x) has a period of 2π/10 = π/5. The solid line completes one full cycle in a larger interval than the dashed line, therefore the solid line is f(x) and corresponds to y = 3sin(5x). The dashed line is g(x) and corresponds to y = 3sin(10x).
Step 2: Find the value of a
'a' represents the x-coordinate where the first minimum of g(x) occurs. Since the period of g(x) is π/5, the first minimum occurs at x = (3π/10). Since we must round to three decimal places: a = 3π/10 ≈ 0.942.
Step 3: Find the value of b
'b' represents the x-coordinate where f(x) first intersects the x-axis after x=0. One full cycle of f(x) = 3sin(5x) is completed at x = 2π/5. Since sin(5x) = 0 when 5x = π, 2π, 3π, ... we see that the first intersection with the x-axis after x = 0 occurs when 5x = π so x = π/5. Therefore, b = π/5 ≈ 0.628
Final Answer:
The graph of y = 3sin(5x) is f(x).
a = 0.942
b = 0.628