Which transformation are needed to change the parent cosine function to y=3cos (10 (x-pi))

It's B or C

Step-by-step explanation:

First, we can transform y = cos (x) to y = 3*cos (x) by stretching the graph vertically by a factor of 3. At x = 0, the y value would now be 3 * 1 = 3 instead of 1 (the stretching would cause all new y-values to be 3 times their original values for any given x).

Now transforming y = 3*cos (x) to y = 3*cos (10*x) will stretch the graph horizontally by a factor of 10 (for any given y value, the new x value corresponding to it is 10 times the original x value).

Finally, to transform y = 3*cos (10*x) to y = 3*cos (10 (x-pi)), shift the graph to the right by pi.