Tangent equation of a point P (2.8 / 3) passing through the square of the curve y = 1 / 3x

Tangent equation of a point P (2.8 / 3) passing through the square of the curve y = 1 / 3x

a>=0
Then f (a) = a (a + 1) = - 2
a²+a+2=0
unsolvable
x=0
So f (- x) = - x (- x + 1) = x & sup2; - X
Odd function
f(x)=-f(-x)=-x²+x
Then a