a) The expression is $\"image\"$

At $\"image\"$

$\"\"$

Differentiating above equation with recept to x.

$\"image\"$

The tangent line to the curve at $\"image\"$ .

$\"image\"$

The equation of the line tangent $\"image\"$ and the point $\"\"$ .

The point -slope form of equation of a line : $\"image\"$ , where m = slope.

$\"\"$

The equation is $\"\"$