Q10 of 268 Page 4

If tan A= 4/3. Find the other trigonometric ratios of the angle A.



We know that,



Or


Here, θ = A



Let,


The side opposite to angle A =BC = 4k


The side adjacent to angle A =AB = 3k


where k is any positive integer


Firstly we have to find the value of AC.


So, we can find the value of AC with the help of Pythagoras theorem


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


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


(AC)2 = 9 k2 +16 k2


(AC)2 = 25 k2


AC =25 k2


AC =±5k


But side AC can’t be negative. So, AC = 5k


Now, we will find the sin A and cos A



Side opposite to angle A = BC = 4k


and Hypotenuse = AC = 5k


So,


Now, We know that



Side adjacent to angle A = AB = 3k


and Hypotenuse = AC = 5k


So,


Now, we find other trigonometric ratios











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