# GATE Questions & Answers of Directional derivatives

## What is the Weightage of Directional derivatives in GATE Exam?

Total 2 Questions have been asked from Directional derivatives topic of Calculus subject in previous GATE papers. Average marks 2.00.

For a scalar function f(x,y,z) = x2 +3y2 +2z2, the directional derivative at the point P(1,2,-1) in the direction of a vector $\stackrel{\to }{i}-\stackrel{\to }{j}+2\stackrel{\to }{k}$ is

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The inner (dot) product of two vectors $\overline{\mathrm P}$ and $\overline{\mathrm Q}$ is zero. The angle (degrees) between the two vectors is