x=t-2sint, y=1-2cost

show that the curve crosses the x axis where t=pi/3 and t=5pi/3

I understand that you have to solve y=0 but alli can get is t=pi/3

can't you just put both t's into the equation for y and show that y = 0 and therefor it's crossing the x axis?

Always graph if at all possible.

I could but I don't have access to a graph creator and no be cause that would be the wrong way of answering that qn and I wouldn't get marks, I have to solve y=0 which makes cost=1/2 which makes t=pi/3 but I cannot find out how to make it also equal 5pi/3

2{\pi}-\frac{\pi}{3}=\frac{5{\pi}}{3}

I'd say get familiar with the unit circle. This is the properties of the trig functions you should know.

0=1-2cos(t)

cos(t)=\frac{1}{2}

t=\frac{(6C+1){\pi}}{3} \;\ or \;\ \frac{(6C-1){\pi}}{3}

If C=0, then t=\pm\frac{\pi}{3}

If C=1, then t=\frac{7\pi}{3} \;\ or \;\ \frac{5\pi}{3}

If C=2, then t=\frac{13\pi}{3} \;\ or \;\ \frac{11\pi}{3}

and so on...

Though, anything that exceeds 2Pi you probably can disregard.

Thank you, guess I need to read up on my C3 then