The functions are  and 

The functions is .

Differentiate with respect to .

The product rule of the deivative:

The slope .

The function is .

Apply derivative on each side wih respect to

.

The slope .

When two functions are Orthogonal .

Substitute and in the equation .

hence the two functions are Orthonogonal

  The functions are nd 

consider and in the above equations.

and

  and .

Graph :

Observe from the graph :

Both the tangents are orthogonal to each other.

  The functions are nd 

The tangents lines are   and .

consider and in the above equations.

and

  and .

Graph:

Observe from the graph :

Both the tangents are orthogonal to each other.

Both the tangents are orthogonal to each other.