The phrase "a formidable task of" is correct and usable in written English.
It can be used when describing a challenging or difficult task that requires significant effort or skill to accomplish.
Example: "Completing the project within the tight deadline was a formidable task of great importance to the team."
Alternatives: "a daunting challenge of" or "a significant undertaking of".
It's a formidable task for one of the world's largest automakers.
The need for the identification of new targets in treating pathogen infection in light of the growing emergence of resistance against antibiotics is a formidable task for the discovery of novel anti-infectives.
To synthesize a protein consisting of 51 amino acids was a formidable task, so it was the spirit of welcoming a challenge that helped the Chinese scientists gain the respect of the world.
First, coordinating motion is a formidable task because of the infinite degrees of freedom that have to be controlled; and second, it is hard to use body coordinates in this flexible animal to represent sensory information in a central control system.
Performance optimization for these contemporary big data processing frameworks on modern High-Performance Computisg (HPC) systems is a formidable task because of the numerous configuration possibilities in each of them.
Merely to acquire the knowledge essential as a basis for the exercise of this multitude of judgments would be a formidable task; and each of the thousands of these judgments would call for some measure of prophecy.
A rigorous direct numerical simulation (DNS) of percolating flows is a formidable task due to intricacies of internal boundaries of the pore space.
[C2.] China Airlines Repairing Its Image Sandy K. Y. Liu faces a formidable task as president of the airline, which had three crashes in the 1990's and needs a major reorganization to restore its image.
As the newly appointed CEO of the Surfrider Foundation, one of the nation's largest grass roots environmental organizations, Nelsen has a formidable task in front of him.
