How do you sketch y = 2 cos 3 (x - (pi/4))y=2cos3(x(π4))?

1 Answer
Jun 7, 2018

As below.

Explanation:

Standard form cosine function is y = A cos (Bx - C) + Dy=Acos(BxC)+D

Given y = 2 cos 3(x - pi/4) = 2 cos (3x - (3pi)/4)y=2cos3(xπ4)=2cos(3x3π4)

Amplitude = |A| = 2Amplitude=|A|=2

"Period " = (2pi) / |B| = (2pi) / 3Period =2π|B|=2π3

"Phase Shift " = -C / B = ((3pi)/4) / 3 = pi/4Phase Shift =CB=3π43=π4, color(red)(pi/4π4 to the right

"Vertical Shift " = D = 0Vertical Shift =D=0

graph{2 cos (3x - (3pi)/4) [-10, 10, -5, 5]}