Q. 7 B4.0( 14 Votes )

If calculate cos A and tan A.

Answer :

Given: Sin A


We know that,



Or



Let,


Side opposite to angle θ = BC =3k


and Hypotenuse = AC =4k


where, k is any positive integer


So, by Pythagoras theorem, we can find the third side of a triangle


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


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


(AB)2 + 9k2 = 16k2


(AB)2 = 16 k2 – 9 k2


(AB)2 = 7 k2


AB =k7


So, AB = k√7


Now, we have to find the value of cos A and tan A


We know that,



Here, θ = A


The side adjacent to angle A = AB =k√7


Hypotenuse = AC =4k


So,


Now,


We know that,




The side opposite to angle A = BC =3k


The side adjacent to angle A = AB =k√7


So,


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