Let `P_1` denote the equation of a plane to which the vector `( hat i+ hat j)` is normal and which contais the line whose equation is ` vec r= hat i+ hat j+ hat k+lambda( hat i- hat j- hat k)a n dP_2` denote the equation of the plane containing the line `L` and a point with position vector ` hat jdot` Which of the following holds good? a. The equation of `P_1` is x+y=2. b. The equation of `P_2` is `vec(r) . (i-2j+k) = 2` c. The acute angle between `P_1` and `P_2` is `cot^(-1) sqrt(3)` d. The angle between plane `P_2` and the line L is ` tan^(-1) sqrt(3)`