The phrase "a complicated expression" is correct and usable in written English.
It can be used when referring to a phrase, statement, or mathematical expression that is intricate or difficult to understand.
Example: "The mathematician presented a complicated expression that took the students a while to decipher."
Alternatives: "a complex phrase" or "an intricate statement".
He is a slight, fresh-faced teen, wearing a T-shirt depicting the NASA logo, a pair of hipster eyeglasses, and a complicated expression that suggests some mixture of surprise, fear, hurt, and resentment.
Maybe it's a complicated expression of his masculinity—"a deep subconscious straight boy fantasy," he speculates in his essay or a testament to the solitude that cars afford those with hermetic tendencies.
Incorporating this effect, the stopping number of an electron is given by a complicated expression that involves a different arrangement of the parameters found in the stopping number of heavy charged particles; i.e., This stopping-power formula has a wide range of validity, from approximately a few hundred electron volts to a few million electron volts in materials of low atomic number.
However, a closed-form solution is not obvious due to a complicated expression of the first-order derivative as shown in (32) in Appendix 1.
Because of the number of loci, the solution for a P,0 is a complicated expression.
The non-imprinted equilibrium is a complicated expression that reduces as expected to 3 when q = 1.
For example, you might use a fairly complicated expression to determine the nearest gas station to a given moving van.
In this case, we have to establish a more complicated expression of operator T and to find the proper lower and upper bounds of Green's functions (Lemma 2.2 and Lemma 2.4).
In C. ocellatus, we detected a far more complicated expression profile of cadherins with significant upregulation of CDH1 (epithelial cadherin), 2, 4, 11, 15, 22, and 24 and downregulation of CDH5 and 13.
Actually, for "finite" ℓ, the total number is given by an explicit but complicated expression.
