Sketch the curve of r=1+2costheta
intercepts at 1 because cos90=0 and -1 since cos is an 'even function', meaning its symmetrical with the horizontal polar axis as the mirror line.
cos theta takes values between -1 and 1 where 1 (at theta=0) gives 3 to be biggest value for r
r=0 is when costheta is 2*pi/3. plot the rest symmetrically and it gives a graph like so
the inside loop is when r<0, would you need to plot this on an exam question?
since cos is an even function, what is sin? how would you solve this with cartesian coordinates, or is it best untouched? am i missing anything out in my working/any way to work it out faster (other than using a graphical calculator)
Should I still go?