The figure depicts a simplistic optical fiber: a plastic core (n1 = 1.54) is surrounded by a plastic sheath (n2 = 1.50). A light ray is incident on one end of the fiber at angle . The rays is to undergo total internal reflection at point A, where it encounters the core-sheath boundary. (Thus there is no loss of light through that boundary.) What is the maximum value of that allows total internal reflection at A