Question

Question #5716a

Answer 1

`sqrt a / 2`

Explanation:

Here, both #x and a >=0.

`y'=sqrt a-a/(2sqrt x)`

At@`x = a, y = 0, y'= sqrt a - a/(2sqrt a)=sqrt a- sqrt a /2= sqrt a /2`.

The equation of the tangent here is

`y = sqrt a/2 ( x - a)`