Simplify the expression: (cscy + coty)(cscy-coty) / cscy
Try using these trig identities to solve your problems: http://en.wikipedia.org/wiki/List_of_trigonometric_identities
\(\bf \cfrac{[cos(y)+cot(y)][csc(y)-cot(y)]}{csc(y)} ?\)
[csc(y) + cot(y)][csc(y) - cot(y)] / csc(y)
hmmm actaully \(\bf \cfrac{[csc(y)+cot(y)][csc(y)-cot(y)]}{csc(y)} ?\) I meant anyhow, had a typo
Yes
\(\bf \cfrac{[csc(y)+cot(y)][csc(y)-cot(y)]}{csc(y)} \\ \quad \\ \textit{difference of squares} \\ \quad \\ (a-b)(a+b) = a^2-b^2\qquad \qquad a^2-b^2 = (a-b)(a+b)\\ \quad \\ \quad \\ \cfrac{csc^2(y)-cot^2(y)}{csc(y)}\implies \cfrac{\cancel{csc^2(y)}}{\cancel{csc(y)}}- \cfrac{cot^2(y)}{csc(y)} \\ \quad \\ csc(y)- \cfrac{cot^2(y)}{csc(y)}\implies \cfrac{1}{sin(y)}-\cfrac{\frac{cos^2(y)}{sin^2(y)}}{\frac{1}{sin(y)}} \\ \quad \\ \cfrac{1}{sin(y)}-\cfrac{cos^2(y)}{\cancel{sin^2(y)}}\cdot \cfrac{\cancel{sin(y)}}{1}\implies \cfrac{1}{sin(y)}-\cfrac{cos^2(y)}{sin(y)} \\ \quad \\ \cfrac{cos^2(y)}{sin^2(y)}\implies ?\)
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