Trig Identies

## (TanX)-1)/(Tan(X)+1) = (1-cot(X))/(1+cot(X))

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# 1 Answer

(TanX)-1)/(Tan(X)+1) = (1-cot(X))/(1+cot(X))

Let's make the "right side" of the equation look like the left:

(1-cot(X))/(1+cot(X))

since cot(x) = 1/tan(x) we can rewrite as:

(1-1/tan(x))/(1+1/tan(x))

(1-1/tan(x))/(1+1/tan(x)) * tan(x)/tan(x)

(tax(x)-1)/(tan(x)+1) (which is exactly like the left side)