HSC Science (Electronics) 12th Board ExamMaharashtra State Board
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# Solution - Find the Angle Between the Planes r(2i+j-k)=3 - HSC Science (Electronics) 12th Board Exam - Mathematics and Statistics

#### Question

Find the angle between the planes bar r.(2bar i+barj-bark)=3 and bar r.(hati+2hatj+hatk)=1

#### Solution

Given planes are:

barr.(2hati+hatj-hatk)=3 and bar r.(hati+2hatj+hatk)=1

The angle between two planes with direction ratios,

(a_1,b_1,c_1)  and (a_2,b_2,c_2)  is

costheta=(a_1a_2+b_1b_2+c_1c_2)/(sqrt(a_1^2+b_1^2+c_1^2) sqrt(a_2^2+b_2^2+c_2^2))

costheta=(2xx1+1xx2-1xx1)/(sqrt(2^2+1^2+(-1)^2) sqrt (1^2+2^2+1^2))

costheta=3/(sqrt6.sqrt6)

costheta=3/6

costheta=1/2

costheta=cos(pi/3)

theta=pi/3

Is there an error in this question or solution?

#### APPEARS IN

2014-2015 (March) (with solutions)
Question 1.2.3 | 2 marks

#### Reference Material

Solution for question: Find the Angle Between the Planes r(2i+j-k)=3 concept: Angle Between Two Planes. For the courses HSC Science (Electronics), HSC Science (Computer Science), HSC Arts, HSC Science (General)
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