Persamaan garis singgung kurva y= akar x di titik (4,2) ? Tolong bantu

y = Vx
y = x^1/2
y' = 1/2x^(1/2-1)
y' = 1/2x^-1/2
y' = 1/2Vx
y' = 1/2V4
y' = 1
Persamaan garis singgung
y - y1 = m (x - x1)
y - 2 = 1(x - 4)
y - 2 = x - 4
y = x -2 atau x - y - 2 = 0