find all solutions of the equation in the interval 02pi tan2
find all solutions of the equation in the interval [0,2pi)
tan^2x-secx=1
write your answer in radians in terms of pi
Solution
tan^2x - secx = 1
sec^2 x - sec x - 2 = 0
Let sec x = y
Then y^2 - y - 2 = 0
y = sec x = 2 ======> cos x = 1/2 =====> x = pi/3, 5pi/3
y = sec x = -1 =====> cos x = -1 =====> x = pi
