Evaluate `int_(-1)^(1) (x-[x])dx` , where [.] denotes the greatest integer function.

Answer

B

Explanation

The coordinates of the incenter are given as follows:
`bar(x) = (20(-8)+15(-15)+25(1))/(20+15+25) = -6`
`bar(y) = (20(5)+15(-19)+25(-7))/(60) = -6`
Hence, incenter I is (-6, -6).
Now, the equation of side PR is
`y+7 = (12)/(-9)(x-1)`
or 4x-4 = -3y-21
or 4x+3y+17 = 0
Inradius is given as the distance of I from side PR, i.e.,
`(|-24-18+17|)/(5) = 5`