transforms

While I was converting this with the inverse phasor transform, I wanna ask a question P{ -4 cos(200t – 45°)} Should I say -4∠-45 or 4∠-45 ? I mean, do I have to preserve the negativity of the magnitude which is "4"? As far as I have known that the magnitude is not a vectorial thing and then...

So i am trying to calculate the fourier transform of this waveform. I have made an attempt at it but i dont think its right: S(t) = 1000t The integral of: 1000t*e^-jwt dt , with the limits: 0 to 1x10^-3