If $tan^2x - 3sec^2x + 3 = 0$, then the value of x(0 ≤ x ≤ 90°) is :

60° 0° 30° 45°

0°

Using :- sec²x - tan²x = 1 Given :- tan²x - 3sec²x + 3 = 0 tan²x - 3 ( 1 + tan²x ) + 3 = 0 tan²x - 3 - 3 tan²x + 3 = 0 - 2 tan²x = 0 tanx = 0 { we know,    tan 0º = 0 } So , x = 0º