Question 139317: cot x -tan x = 2
Answer by edjones(8007)   (Show Source):
You can put this solution on YOUR website! cot x -tan x = 2
1/tan(x) - tan(x)=2
1-tan^2(x)=2tan(x) multiply each side by tan(x) to eliminate fractions.
tan^2(x)+2tan(x)-1=0
tan^2(x)+2tan(x) =1
tan^2(x)+2tan(x)+1=1+1 completing the square
(tan(x)+1)^2=2
tan(x)+1=+-sqrt(2)
tan(x)=-1+sqrt(2), tan(x)=-1-sqrt(2)
x=-67.5 deg, x=22.5 deg
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Ed
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