y = 8sin[(x/4)-(π/8)]= 8sin[( 1/4)*(x-π/2)]

The image of the above function is y=sinx. First move π/2 units to the right, then expand the abscissa by 4 times and the ordinate by 8 times.

(2)y =( 1/3)sin[3x+(π/7)]=( 1/3)sin[3 *(x+π/2 1)]

The image with y=sinx is shifted to the left by π/2 1 unit, then the abscissa is expanded by 3 times, and the ordinate is reduced to 1/3 times. 3. Draw trigonometric functions in high school mathematics (guidance)

1. Draw a picture, and write down the amplitude, period and initial phase of the following functions, and explain how the images of these functions are obtained from sine curves (pay attention to the definition domain):

( 1)y=8sin[(x/4)-(π/8)]，x∈[0，+∞)

(2)y=( 1/3)sin[3x+(π/7)]，x∈[0，+∞)

Draw a picture and tell me which points to draw.