= Solution
At1000nm the first-zero radius is $5.083\times10^{-7}\,\mathrm{rad}$, slightly larger than the $5.00\times10^{-7}\,\mathrm{rad}$ separation. The images therefore overlap strongly and \b[just fail the conventional <Rayleigh criterion>], rather than forming two clean isolated peaks.
The summed Airy profile can still have a shallow central dip and two local maxima: Rayleigh's criterion is a resolution convention, not the exact condition for a profile to become single-peaked. The two-panel original plot in part(a) shows the correct intensity sums at both wavelengths. <University Physics Volume 3 by Samuel J. Ling and others>[§4.5, resolution criterion for equal point sources]{ref}
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