If a 1 , b 1 , c 1 , a 2 , b 2 , c 2 are the direction cosines of two lines making an angle θ with each other, then cos θ =

Question

If a 1 , b 1 , c 1 , a 2 , b 2 , c 2 are the direction cosines of two lines making an angle &#952; with each other, then cos &#952; =

Aicharya · Accepted Answer

Since a 1 , b 1 , c 1 , a 2 , b 2 , c 2 are direction cosines of the two lines. &#8658; a 1 2 + b 1 2 + c 1 2 = 1 &#160; &#38; &#160; a 2 2 + b 2 2 + c 2 2 = 1 Now, cos &#952; = ( a 1 a 2 + b 1 b 2 + c 1 c 2 ) a 1 2 + b 1 2 + c 1 2 a 2 2 + b 2 2 + c 2 2 &#8658; cos &#952; = ( a 1 a 2 + b 1 b 2 + c 1 c 2 ) .

If a 1 , b 1 , c 1 , a 2 , b 2 , c 2 are the direction cosines of two lines making an angle θ with each…

Solution

If a 1 , b 1 , c 1 , a 2 , b 2 , c 2 are the direction cosines of two lines making an angle &#952; with each…

Solution

If a 1 , b 1 , c 1 , a 2 , b 2 , c 2 are the direction cosines of two lines making an angle θ with each…