The expression (tan x + cot x)^2 is the same as ____? Please help and explain. Thank you!
(a+b)^2=a^2+2ab+b^2
What do I do with this formula do I plug something in?
you have (a+b)^2 where a=tan(x) and b=cot(x) don't you?
\[(\tan(x)+\cot(x))^2\\ (\tan(x)+\cot(x)) \cdot (\tan(x)+\cot(x)) \\ \tan(x)(\tan(x)+\cot(x))+\cot(x)(\tan(x)+\cot(x)) \\ \tan^2(x)+\tan(x)\cot(x)+\cot(x)\tan(x)+\cot^2(x)\] are you can take this longer route if you don't know (a+b)^2=a^2+2ab+b^2
combine like terms there
\[\huge\ (a+b)^2 = (a + b)(a+b)\] this is example now use foil method
also you should know a little fact about tan(x)*cot(x)
you might also find the Pythagorean identities helpful here too
\[\sin^2(x)+\cos^2(x)=1 \\ \tan^2(x)+1=\sec^2(x) \\ 1+\cot^2(x)=\csc^2(x)\]
@freckles The answer looks like it is B. sec^2 x + csc^2 x
sounds right tan^2(x)+1+1+cot^2(x) sec^2(x) + csc^2(x) :)
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