If 3 cot A = 4, check whetheror not

It is given that 3cot A = 4

Or, cot A =


Consider a right triangle ABC, right-angled at point B



Cot A =


=


If AB is 4k, then BC will be 3k, where k is a positive integer


In ΔABC,


(AC)2 = (AB)2 + (BC)2


= (4k)2 + (3k)2


= 16k2 + 9k2


= 25k2


AC = 5k


Cos A =


=


=


Sin A =


=


=


Tan A =


=


=


1 – tan2A/1 + tan2A =


=


= =


Cos2A – Sin2A = 2 2


=


=


Therefore,


1 – tan2A/1 + tan2A = Cos2A – Sin2A


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