Consider the curve represented by 

1. Find the gradient of the curve at any point    (2 marks)
2. Find the equation of the tangent to the curve at the point    and find the equation of the tangent to the curve at the point

    

   Write each equation in the form    (2 marks)

3. Find the acute angle between the tangent to the curve at the point    and the tangent to the curve at the point 

    

   Give your answer in the form  , where is a real constant  (2 marks)