Question

If cos theta=0.6, show that:-
(5 sin theta - 3 tan theta)=0​

Answer 1

Answer:

given cos A = 0.6

to prove (5 sin A - 3 tan A) = 0

cos A = 0.6 = 6/10 = 3/5

as cos of any angle is (adjacent side/hypotenuse)

adj = 3k hypotenuse = 5k then by applying Pythagoras theorem ,

opposite side = √ (5k)^2 - (3k)^2

= √(25k^2 - 9k^2)

= √(16k^2)

=> 4k

now sin A = opp/hyp = 4k/5k = 4/5

tan A = opp/adj = 4k/3k = 4/3

therefore LHS = (5 sinA - 3 tan A)

= (5*4/5 - 3*4/3)

= 4 - 4 = 0 = RHS