Practicing Success
If $sec^2 x - 3 sec x + 2 = 0$, then the value of x(0 < x < 90°) is : |
45° 15° 60° 30° |
60° |
$sec^2 x - 3 sec x + 2 = 0$ sec²x - 2.secx - secx + 2 = 0 secx ( secx - 2 ) - 1 ( secx - 2 ) = 0 (secx - 1).(secx - 2) = 0 Either secx - 1 = 0 OR secx - 2 = 0 { secx - 1 = 0 not possible because 0 < x < 90°.} So, secx - 2 = 0 secx = 2 { we know, sec60° = 2 } so, x = 60° |