Posted by asaereay on .
find the equation of the tangent line to f(x)=square root x passing through (4,0)

AP Calc. 
Reiny,
y = √x = x^(1/2)
dy/dx = (1/2)x^(1/2) = 1/(2√x)
so at (4,0), dy/dx = 1/2√4 > undefined in the real numbers
uh uh!!
look at y = √x, the point (4,0) does not lie on your curve, so ...... bogus question
check your typing