the Further Mathematics network www.fmnetwork.org.uk the Further Mathematics network www.fmnetwork.org.uk FP2 (MEI) Polar coordinates and curves, the area of a sector Let Maths take you Further… Polar coordinates and curves, the area of a sector Before you start: You need to know only basic trigonometry and Pythagoras’ theorem for this section. However, the work on the modulus-argument form of a complex number from Further Pure 1 will be useful as similar techniques are used here. You need to be able to differentiate a function defined implicitly (Core 3 chapter 4). You need to be confident with all types of integration covered so far, in particular integration of sin x and cos x (Core 3 chapter 5). You also need to be able to use trigonometric identities in integration, in particular for integrating sin² x and cos² x (page 3 of the FP2 textbook). Polar coordinates and curves, the area of a sector When you have finished… You should: Understand the meaning of polar co-ordinates (r, θ) and be able to convert from polar to cartesian co-ordinates and vice-versa (page 21). Be able to sketch curves with simple polar equations (pages 23 – 26). Be able to find the area enclosed by a polar curve (pages 27 – 28). Conversion between Cartesian and Polar Coordinates Example Equations of curves Curve Sketching Sketch on polar paper the graph of r 4 cos Use the graph y=4cosx to help Sketch on polar paper the graph of r 4 cos 3 rhodonea Autograph Demonstration r k r a b cos r a sin n r a cos n Use the constant controller in autograph to determine how the values of the constants (a,b,n and k) effect the curve Area of a sector Polar coordinates and curves, the area of a sector When you have finished… You should: Understand the meaning of polar co-ordinates (r, θ) and be able to convert from polar to cartesian co-ordinates and vice-versa (page 21). Be able to sketch curves with simple polar equations (pages 23 – 26). Be able to find the area enclosed by a polar curve (pages 27 – 28). Independent study: Using the MEI online resources complete the study plan for Polar coordinates 1 and Polar coordinates 2 Do the online multiple choice tests for these sections and submit your answers online.