Find the area bounded by the curve between and .
4 square units
Explanation
Following the same method as Example 4 in the textbook for y = cos x, we need to split the region based on where sin x is positive or negative. The curve y = sin x is above x-axis for x ∈ (0, π) and below x-axis for x ∈ (π, 2π). We take absolute value for the region below x-axis to get positive area.
Solution Steps
Step 1: Identify regions where y = sin x is above/below x-axis. For x ∈ (0, π), sin x > 0 (above x-axis). For x ∈ (π, 2π), sin x < 0 (below x-axis).
Step 2: Set up the required area = ∫₀^π sin x dx + |∫_π^{2π} sin x dx|
Step 3: Calculate ∫₀^π sin x dx = [-cos x]₀^π = -cos π - (-cos 0) = -(-1) + 1 = 1 + 1 = 2
Step 4: Calculate ∫_π^{2π} sin x dx = [-cos x]_π^{2π} = -cos 2π - (-cos π) = -1 - 1 = -2. Taking absolute value: |-2| = 2
Step 5: Total required area = 2 + 2 = 4 square units