X-2Y=0,Y=1/2*X
y=SINx
y'=cosx
令y'=cosx=1/2得
x=2kπ+π/3,此时,sinx=√3/2
或x=2kπ-π/3,此时,
sinx=-√3/2
故P坐标为(2kπ+π/3,√3/2)
或(2kπ-π/3,-√3/2)
X-2Y=0,Y=1/2*X
y=SINx
y'=cosx
令y'=cosx=1/2得
x=2kπ+π/3,此时,sinx=√3/2
或x=2kπ-π/3,此时,
sinx=-√3/2
故P坐标为(2kπ+π/3,√3/2)
或(2kπ-π/3,-√3/2)