1.

The angle between two planes `x+2y+2z=3` and `-5x+3y+4z=9` isA. `cos^(-1).(0sqrt(2))/(20)`B. `cos^(-1).(3sqrt(2))/(5)`C. `cos^(-1).(3sqrt(2))/(10)`D. `cos^(-1).(19sqrt(2))/(30)`

Answer» Correct Answer - C
Here , `a_1=1,b_1=2,c_1=2`
and `a_2=-5,b_2=3, c_2=4`
`therefore cos theta =(1xx (-5)+2xx3+2xx4)/(sqrt(1+2^2+2^2)sqrt(5^2)+3^2+4^2)=(-5+6+8)/(sqrt(9)+sqrt(50))=(3sqrt(2))/(10)`
`rArr theta=cos^(-1)((3sqrt(2))/(10))`


Discussion

No Comment Found

Related InterviewSolutions