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

Capuchin

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?

galactus

Always graph if at all possible.

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albear

i could but i dont have access to a graph creator and no be cause that would be the wrong way of answering that qn and i wouldnt 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

galactus

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







If C=0, then

If C=1, then

If C=2, then

and so on............

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

albear

thank you, guess i need to read up on my C3 then