Question 29986
Either switch your calculator to radians and type in (7*pi)/6 and then find te sin of that. Etc


or convert the radians to degrees first and then find te sin etc.


I shall do the second method, since the first is just you using a calculator.


ALWAYS START WITH WHAT YOU KNOW: {{{2*pi}}} radians is 360 degrees


So, {{{pi = 180}}}


Hence {{{(7*pi)/6 = (7/6)*180}}}
which is 210 degrees


So sin210 is? use your calculator here. Or, if you truly understand TRIG manipulation, do it by yourself: realise that 210 degrees is in the 3rd quadrant, where sin is always -ve. The equivalent 1st quadrant angle here would be 180+x = 210 --> x is 30. So sin30 is 1/2. 


Answer is -(1/2)...check on your calculator that this is correct :-)


You do the rest :-)


jon.