The value of ⎡⎢ ⎢ ⎢⎣1−tanθ4tanθ41⎤⎥ ⎥ ⎥⎦⎡⎢ ⎢ ⎢⎣1tanθ4−tanθ41⎤⎥ ⎥ ⎥⎦−1 is
If z=1−cos θ+i sin θ, then |z|=