and plug in this term into the first equation:
This one is for you!
2) Eliminate t to give an equation that relates x and y.
x=tan(t) and y=sec^2(t)-31. Re-arrange the equation:
3) Show that this equation represents a circle by rearranging it into the centre-radius form of the equation of a circle. State the coordinates of the center and the radius of the circle:
2. Complete the squares:
3. Divide the equation by the leading factor of the brackets on the LHS:
4. Determine the coordinates of the centre and the length of the radius.