Question 1114560
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It would help us to help you if you showed us your work -- instead of simply saying your tried it and it didn't work.<br>
This one works out very nicely if you use (a-b)^2 to expand the right hand side.<br>
{{{(cscx-cotx)^2 = (1/sinx-cosx/sinx)^2 = (1-cosx)^2/(sinx)^2}}}<br>
Then use the most common trig identity (which you will use 10 times as often as all the others together) to get the expression in terms of cosx only:<br>
{{{(1-cosx)^2/(sinx)^2 = (1-cosx)^2/(1-cosx^2) = (1-cosx)^2/((1+cosx)(1-cosx)) = (1-cosx)/(1+cosx)}}}