sin图像和cos图像数学中有将sin或cos图像进行移动的题目,请问大家先平移...

Question

sin图像和cos图像 数学中有将sin或cos图像进行移动的题目,请问大家先平移在吧x坐标扩大怎么做,先扩大x坐标在平移怎么做?例题 sin(x+π/4）先把X大2倍,在平移π/3 和sin(x+π/4）先平移π/3,在把X扩大2倍

Answer 1

把横坐标扩大为2倍,则x的系数乘1/2sin(x/2+π/4)假设是向左移π/3则x换成x+π/3sin[(x+π/3)/2+π/4]=sin(x/2+5π/12)如果是向右移则x换成x-π/3先左移π/3则x换成x+π/3=sin[(x+π/3)+π/4]=sin(x+7π/12)在横坐标扩大为2倍,则x的系数乘1/2是sin(x/2+7π/12)