Concept:Here,
⌈x⌉ denotes the integral part of
x, which is the greatest integer less than or equal to
x.
So
f(x)=x−⌈x⌉ is the fractional part of
x, and it is evaluated piecewise on
[−1,0) and
[0,1).
Explanation:For
−1≤x<0, we have
⌈x⌉=−1.
Therefore,
f(x)=x−(−1)=x+1.
For
0≤x<1, we have
⌈x⌉=0.
Therefore,
f(x)=x−0=x.
Now split the integral over these two intervals:
∫−11f(x)dx=∫−10(x+1)dx+∫01xdxEvaluate the first integral:
∫−10(x+1)dx=[2x2+x]−10=0−(21−1)=21Evaluate the second integral:
∫01xdx=[2x2]01=21Adding these results:
21+21=1Answer:∫−11f(x)dx=1Hence, the correct option is A.