Answer:
D
Step-by-step explanation:
Assuming that the expression is referring to sin²(2πft) and not sin²(2)πft, we can solve as follows:
One trigonometric identity states that sin²x+cos²x = 1. We want to express this in terms of cos²x, so we need to solve for sin²x. Subtracting cos²x from both sides, we get 1-cos²x = sin²x. Plugging (2πft) for x, we get
1-cos²(2πft) = sin²(2πft)
We can plug that into our equation to get
P = I₀²R(1-cos²(2πft)), or D
