Suppose that {Yt} is stationary with autocovariance function γk. (a) Show that Wt = ∇Yt = Yt − Yt − 1 is stationary by finding the mean and autocovariance function for {Wt}. (b)Show that Ut = ∇2Yt = ∇[Yt − Yt−1] = Yt −

Graphic design is still art, although it differs highly from the traditional forms of art. when someone is creating a piece of art using technology, it still takes time, effort, and creativity to make something look visually appealing. art itself is defined as "the expression or application of human creative skill and imagination." working on computers and using design programs still require the artist to understand lines, shape, form, value, color, space,  and all of the other elements that traditional artists study. they still need to be able to evoke thoughts and emotions through their piece. art does not have to be physically created for it to count as art. so, i think graphic design should still be considered art.

He could go with d. temperatempera coloring is very precise and can easily be used if you have the skills necessary to paint hair. this was commonly seen in religious paintings made with tempera techniques. the first tree are not that much about fine details and photorealism and are more about vivid colors and expressiveness.

Douglas s freeman wrote an account of the life of robert e lee

It has been trivialized in ads and cartoons.