The curve y=sinx oscillates above and below the x-axis. Area is always positive, so the absolute value of the function must be used where it is negative.
For the interval −2π≤x≤2π:
sinx≥0 on [−π,0] and [0,π]
sinx<0 on [−2π,−π] and [π,2π]
For 0≤x≤π, where sinx≥0:
Area =∫0πsinxdx
=[−cosx]0π
=−cosπ−(−cos0)
=−(−1)+1
=2
For π≤x≤2π, where sinx<0:
Area =∫π2π∣sinx∣dx
=∫π2π(−sinx)dx
=[cosx]π2π
=cos2π−cosπ
=1−(−1)
=2
For −π≤x≤0, where sinx≥0:
Area =∫−π0sinxdx
=[−cosx]−π0
=−cos0−(−cos(−π))
=−1+(−1)
=−2
Taking the absolute value: Area =2
For −2π≤x≤−π, where sinx<0:
Area =∫−2π−π∣sinx∣dx
=∫−2π−π(−sinx)dx
=[cosx]−2π−π
=cos(−π)−cos(−2π)
=−1−1
=−2
Taking the absolute value: Area =2
Total Area =2+2+2+2
=8
Therefore, the area of the region bounded by the curve and the x-axis is 8 square units.