This image was acquired from
wikimedia. It was marked as Public Domain or CC0 and is free to use. To verify, go to the source and check the information there.
Keywords from Image Description:
Gradient ascent contour. en The 'gradient ascent' method applied to function This image shows the contourline point of view See also image gradient ascent surface user Joris Gillis Created with Maple using the code below restart with VectorCalculus with plots with plottools sin cos xexp grad VectorCalculusGradient plotd axes