posted by asaereay .
find the equation of the tangent line to f(x)=square root x passing through (-4,0)
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
look at y = √x, the point (-4,0) does not lie on your curve, so ...... bogus question
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