If two lines L1 and L2 with direction ratios (a_1,b_1,c_1 ,and ,a_2,b_2,c_2 ) respectively are perpendicular to each other then (a_1 a_2+b_1 b_2+c_1 c_2=0 )

If two lines L1 and L2 with direction ratios (a_1,b_1,c_1 ,and ,a_2

1.	If two lines L₁ and L₂ with direction ratios (a_1,b_1,c_1 ,and ,a_2,b_2,c_2 ) respectively are perpendicular to each other then (a_1 a_2+b_1 b_2+c_1 c_2=0 )
A.	True
B.	False
Answer» B. False

Find the angle between the pair of lines ( frac{x-3}{5}= frac{y+7}{3}= frac{z-2}{2} ,and , frac{x+1}{3}= frac{y-5}{4}= frac{z+2}{8} ).
If two lines L1 and L2 are having direction cosines (l_1,m_1,n_1 ,and ,l_2,m_2,n_2 ) respectively, then what is the angle between the two lines?
Find the angle between the lines ( vec{r}=2 hat{i}+6 hat{j}- hat{k}+ ( hat{i}-2 hat{j}+3 hat{k}) ) and ( vec{r}=4 hat{i}-7 hat{j}+3 hat{k}+ (5 hat{i}-3 hat{j}+3 hat{k}) ).
If the equations of two lines L1 and L2 are ( vec{r}= vec{a_1}+ vec{b_1} ) and ( vec{r}= vec{a_2}+ vec{b_2} ), then which of the following is the correct formula for the angle between the two lines?
Find the value of p such that the lines ( frac{x+11}{4}= frac{y+3}{-2}= frac{z-3}{4} ,and , frac{x-3}{p}= frac{y+12}{2}= frac{z-3}{-12} ) are at right angles to each other.
If two lines L1 and L2 with direction ratios (a_1,b_1,c_1 ,and ,a_2,b_2,c_2 ) respectively are perpendicular to each other then (a_1 a_2+b_1 b_2+c_1 c_2=0 )
Find the angle between the two lines if the equations of the lines are ( vec{r}= hat{i}+ hat{j}+ hat{k}+ (3 hat{i}- hat{j}+ hat{k}) ,and , vec{r}=4 hat{i}+ hat{j}-2 hat{k}+ (2 hat{i}+3 hat{j}+ hat{k}) )
Find the angle between the lines. ( frac{x+2}{1}= frac{y+5}{6}= frac{z-3}{2} )
If L1 and L2 have the direction ratios (a_1,b_1,c_1 ,and ,a_2,b_2,c_2 ) respectively then what is the angle between the lines?