Question

which transformation causes the described change in the graph of the function y = cos x? the transformation results in a horizontal shrink. the transformation results in a vertical stretch. the transformation results in a horizontal stretch. the transformation results in a vertical shrink

Answer 1

The transformations that can occur to the graph of the function y = cos x that will exhibit changes would be changes to the angle, or changes to the coefficient. The transformations can be viewed as follows:

y = cos x transforms to y = cos (kx)

k > 1 ; a horizontal shrink occurs
0 < k < 1 ; a horizontal stretch occurs

y = cos x transforms to y = A cos x

|A| > 1 ; a vertical stretch occurs
|A| < 1 ; a vertical shrink occurs