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The signal $x(t)$ is described by

$x(t)=\left\{\begin{array}{ll} 1 & \text { for }-1 \leq t \leq+1 \\ 0 & \text { otherwise } \end{array}\right.$

Two of the angular frequencies at which its Fourier transform becomes zero are

1. $\pi, 2 \pi$
2. $0.5 \pi, 1.5 \pi$
3. $0, \pi$
4. $2 \pi, 2.5 \pi$