Would the following working help with question 18?
Integrating, we get:
In order to find the value of this constant, we need to understand that the gradient of the tangent at (-1,3) is perpendicular to the gradient of the line
Rearranging results in:
Therefore, the gradient of the tangent is 2, as the product of perpendicular gradients is -1.
Substituting this into
:
Integrating again, we get:
The point (-1,3) is on this curve. Using this information in the equation:
Hence, the equation of the curve is: