Which transformation was not performed on y=cos x to obtain $y=-4 \cos (2 x+\pi / 3) ?$
A) Vertical stretch by a factor of 4
B) Horizontal stretch by a factor of 2
C) Horizontal shift left by $\pi / 6$ units
D) Reflection through the x -axis.

Question

Which transformation was not performed on  y=cos x  to obtain $y=-4 \cos (2 x+\pi / 3) ?$
A) Vertical stretch by a factor of 4
B) Horizontal stretch by a factor of 2
C) Horizontal shift left by $\pi / 6$ units
D) Reflection through the  x -axis.

Quizplus · Accepted Answer

The transformation $y=-4 \cos (2 x+\pi / 3)$ includes a vertical stretch by a factor of 4 (A), a horizontal compression by a factor of 2 (not a stretch, hence B is incorrect), a horizontal shift to the left by $\pi / 6$ units (C), and a reflection through the x-axis (D).

Which Transformation Was Not Performed on Y=cos X y=−4cos⁡(2x+π/3)?y=-4 \cos (2 x+\pi / 3) ?y=−4cos(2x+π/3)?

Which Transformation Was Not Performed on Y=cos X $y=-4 \cos (2 x+\pi / 3) ?$