Answer:
"changes the period to pi"
Step-by-step explanation:
f(t) = Sin(t),
Here, t is the period, by definition.
Multiply t by a number that is GREATER THAN 1, makes the period shorter and compressed.
Multiplying t by a number that is between 0 and 1 makes the period expanded.
For the first, if we multiply the period by a, the period becomes [tex]\frac{2\pi}{a}[/tex]
Since the problem tells us to multiply by 2, we know the period becomes compressed and becomes :
[tex]\frac{2\pi}{2}=\pi[/tex]
Third answer choice is right.