The phrase "a valid approximation" is correct and usable in written English.
You can use it when discussing estimates or calculations that are reasonably close to the actual value or result.
Example: "In this experiment, we found that our measurements provided a valid approximation of the true temperature."
Alternatives: "a reasonable estimate" or "an acceptable approximation".
Thus, Newton's theory is not incorrect; rather, it constitutes a valid approximation to general relativity under certain conditions.
The persistent obstacle in such processes is to find a valid approximation for soil representation.
Typically, one assumes that the mixing is linear and instantaneous, which is a valid approximation in brain signals[6 ]
Since r2 ≪ 1 in typical applications and U ¯ n ( z ) is a smooth function, this is a valid approximation.
Because the heat effects associated with adsorption are comparatively large, the assumption of isothermal behavior is a valid approximation only when uptake rates are relatively slow.
Because the heat effects associated with adsorption are comparatively large, the assumption of isothermal behaviour is a valid approximation only when uptake rates are relatively slow.
(Note that executing the influence function calculation method only for a fraction of nodes is a possible valid approximation method inside the ModuLand method family, too).
We believe that this exercise constitutes a valid first approximation toward understanding the role of these mutations in human disease.
We show that a Qualitative networks model of a frequent network motif offers a valid qualitative approximation of the experimentally observed behavior of this motif.
The quantitation of cell density using the VIA methods described here relies on the valid approximation that measurement of the total reaction product viewed in a video field (in pixels) is virtually identical to measurement of the summated reaction product (in pixels) around the isolated, individual cells within that same field.
However, restricting to any finite collection of subregions yields a valid outer-approximation of, and hence of.
