Question

The direction ratios of the line which is perpendicular to the lines with direction ratios –1, 2, 2 and 0, 2, 1 are _______.

Options

• –2, –1, –2

• 2, 1, 2

• 2, –1, –2

• –2, 1, –2

Answer 1

–2, 1, –2

`abs [[hat"i",hat"j",hat"k"],[-1,2,2] ,[0,2,1]]`

=`hat "i"(2-4) -hat"j"(-1)+hat"k"(-2)`

= `- 2hat"i" +hat"j" - 2hat"k"`