The argument of 1−i1+i is
−π2
π2
3π2
5π2
Let z = 1−i1+i⇒ z=1−i1+i×1−i1−i⇒ z=1+i2−2i1−i2⇒ z=1−1−2i1+1⇒ z=−2i2 ⇒ z=−i
Since, z lies on negative direction of imaginary axis.
Therefore, arg (z) = −π2
Find the interval(s) in which f(x) = sec(x) is convex.
The trigonometric form of z=(1−i cot8)3 (where i=√−1) is
√(1+sinA)−√(1−sinA)=−2cos(A/2)