Let a plane P1 containing the line L1:x−11=y−1−1=z−1−1 and another plane P2 containing the line L1 and passses through the point (0,1,1). If d.r's of normal to the plane P1 are 1,1,0, then the acute angle between the planes P1 and P2 is equal to

Let a plane P1 containing the line L1:x−11=y−1−1=z−1−1 and a

1.	Let a plane P1 containing the line L1:x−11=y−1−1=z−1−1 and another plane P2 containing the line L1 and passses through the point (0,1,1). If d.r's of normal to the plane P1 are 1,1,0, then the acute angle between the planes P1 and P2 is equal to
Answer» Let a plane $P_{1}$ containing the line $L_{1} : \frac{x - 1}{1} = \frac{y - 1}{- 1} = \frac{z - 1}{- 1}$ and another plane $P_{2}$ containing the line $L_{1}$ and passses through the point $(0, 1, 1) .$ If d.r's of normal to the plane $P_{1}$ are $1, 1, 0,$ then the acute angle between the planes $P_{1}$ and $P_{2}$ is equal to