The region is bounded by:
- y>x1
- y<45x−1 (from 5x−4y−1>0)
- y<417−4x (from 4x+4y−17<0)
Find intersection points:
- Between y=x1 and y=45x−1: x1=45x−1⟹5x2−x−4=0⟹(5x+4)(x−1)=0. Since x>0, x=1.
- Between y=x1 and y=417−4x: x1=417−4x⟹4x2−17x+4=0⟹(4x−1)(x−4)=0. Intersection at x=41 and x=4.
- Between y=45x−1 and y=417−4x: 45x−1=417−4x⟹9x=18⟹x=2.
The region lies between x=1 and x=4. For x∈[1,2], upper bound is 45x−1. For x∈[2,4], upper bound is 417−4x. The lower bound is x1.
Area A=∫12(45x−1−x1)dx+∫24(417−4x−x1)dx
A=[85x2−4x−logex]12+[417x−2x2−logex]24
A=((820−42−loge2)−(85−41−0))+((17−8−loge4)−(434−2−loge2))
A=(2−loge2−83)+(9−2loge2−6.5+loge2)
A=(813−loge2)+(25−loge2)=813+20−2loge2=833−loge4.