# Math Help - f decreases most rapidly at Q

1. ## f decreases most rapidly at Q

Find a unit vector in the direction in which f decreases most rapidly at Q
Thank u!

2. Originally Posted by vincent8818
Find a unit vector in the direction in which f decreases most rapidly at Q
Thank u!
$\nabla f$ is the direction of most rapid increase, so $-\nabla f$ is the direction of most rapid decrease, so now you need only normalise it.

RonL