UTpaper

Free mock tests & test series

Question 161Asked in DSSSB TGT Computer Science, 25 Jun 2023, Shift 2 (12:30 PM)

Find a unit vector normal to the surface x³ + y³ + 3xyz = 3 at the point (1, 2, -1).

Find a unit vector normal to the surface x³ + y³ + 3xyz = 3 at the point (1, 2, -1).
  1. AQuestion content
  2. BQuestion content
  3. CQuestion content
  4. DQuestion content
Show answerHide answer

Correct answer: (C)

Explanation

∇f = (3x² + 3yz, 3y² + 3xz, 3xy). At (1, 2, −1) this is (−3, 9, 6) = 3(−1, 3, 2). Its magnitude is 3√14, so the unit normal is (−î + 3ĵ + 2k̂)/√14.

From DSSSB TGT Computer Science PYQ, 25 Jun 2023, Shift 2 (12:30 PM)

This is question 161 of DSSSB TGT Computer Science PYQ, 25 Jun 2023, Shift 2 (12:30 PM). See all questions of this paper with answers, or attempt the paper as a timed online test to get your score and all-India rank.