If 2 sec2 θ - 9 sec θ + 7 = 0, then what is the value of cos2 θ + sec2 θ ? |
2 3 5 1 |
2 |
2 sec2 θ - 9 sec θ + 7 = 0 2 sec2 θ - 7 sec θ - 2 sec θ + 7 = 0 sec θ ( 2 sec θ - 7 ) - 1 ( 2 sec θ - 7 ) = 0 Either ( 2 sec θ - 7 ) = 0 or ( sec θ - 1 ) = 0 ( 2 sec θ - 7 ) = 0 is not possible. & ( sec θ - 1 ) = 0 sec θ = 1 So, θ = 0º Now, cos2 θ + sec2 θ = cos2 0º + sec2 0º = 1 + 1 = 2 |