MHT CET202613 April 2026Evening ShiftMathematicsThree Dimensional GeometryActual
If a line makes angles , , with the coordinate axes, then the sum of values of ^2 + ^2 + ^2 and 2 + 2 + 2 is ...
Options
- A5
- B0
- C3
- D1
Correct answer
D. 1
Step-by-step solution
The sum to be evaluated is ^2 + ^2 + ^2 + 2 + 2 + 2 . Using the trigonometric identity 2 = ^2 - ^2 , we can write ^2 + 2 = ^2 . Grouping the terms, we get: ( ^2 + 2 ) + ( ^2 + 2 ) + ( ^2 + 2 ) = ^2 + ^2 + ^2 Since , , are the angles made by a line with the coordinate axes, their direction cosines satisfy: ^2 + ^2 + ^2 = 1 Thus, the required sum is 1 . Answer: 1