y=4sin(πx/8+π/4-π)怎样变成y=-4sin(πx/8+π/4）过程~
问题描述：
y=4sin(πx/8+π/4-π)怎样变成y=-4sin(πx/8+π/4）过程~
答
y=4sin(πx/8+π/4-π)怎样变成y=-4sin(πx/8+π/4）y=4sin{-[π-(πx/8+π/4)]}(把[π-(πx/8+π/4)]看作α）=-4sin[π-(πx/8+π/4)](这里用了sin(-α)=-sinα的公式）=-4sin(πx/8+π/4)（把(πx/8+π/4)看作α,...