If 5 sin2 A + 3cos2A = 4, 0 < A < 90o, then what is the value of tan A ?
Answer & explanation
Correct answer: option 3
We are given that :-
5 sin²A + 3 cos²A = 4
2 sin²A + 3 sin²A + 3 cos²A = 4
{ using , sin²A + cos²A = 1 }
2 sin²A + 3 = 4
2 sin²A = 1
sin A = \(\frac{1}{ √2 }\)
{ we know, sin 45º = \(\frac{1}{ √2 }\) }
So, A = 45º
Now,
tan A
= tan 45º
= 1