In the ever-evolving world of fitness and wellness, Tai Chi continues to hold its own as a practice that merges the realms of physical health and mental well-being. As we step into the future, the paradigm of Tai Chi classes is predicted to shift, keeping pace with transformative technology trends and adapting to the global pandemic's residual effects. The trajectory is set towards an integration of ancient knowledge with the dynamic world of virtual reality, artificial intelligence, and online platforms.

Firstly, let us examine the profound roots of this practice, offering us clues about its future trajectory. Tai Chi, originating from ancient China, is a graceful form of exercise that involves a series of movements performed in a slow, focused manner, accompanied by deep breathing. It has been recognized time and again for its potential in stress reduction and a variety of other health conditions.

The advent of technology in Tai Chi learning might seem like a paradox, given the practice's emphasis on mindfulness and relaxation. However, embracing technology has become a necessity of the times, and Tai Chi is no exception. There is a growing trend of online platforms offering Tai Chi classes for different levels of learners. Through video tutorials and live-streamed sessions, these platforms make Tai Chi accessible to a broader audience. Geographic location and time constraints, which were once limiting factors, are no longer barriers to participation.

Artificial Intelligence (AI) is another game-changer. Some AI-powered apps have entered the market, providing personalized Tai Chi training with real-time feedback. Leveraging machine learning algorithms, these apps track and analyze users' movements, compare them with the ideal postures, and provide corrective tips - a sort of virtual instructor, if you will. The implications of this for Tai Chi are substantial, potentially democratizing access and allowing for a more personalized learning experience.

Furthermore, the integration of Virtual Reality (VR) within Tai Chi instruction is a trend on the horizon. Immersive VR environments could provide learners with a near-authentic experience of practicing Tai Chi in traditional settings, such as Chinese gardens or by serene lakes, right in their living rooms. While this might seem speculative, the rapid advancements in VR technology make it a distinct possibility in the not-so-distant future.

The application of Quantified Self, a movement to incorporate technology into data acquisition on aspects of a person's daily life, also holds promise. Wearable technology such as fitness trackers and smartwatches could be employed to monitor parameters like breathing rate, heart rate, and smoothness of movements during Tai Chi practice. The data could then be analyzed for performance enhancement and better health outcomes.

The Covid-19 pandemic has also had a profound impact on Tai Chi classes, necessitating a shift from in-person to online learning. While there is no substitute for the physical presence of an instructor, the move to digital platforms has allowed more people to explore Tai Chi from the comfort of their homes. This trend is likely to continue post-pandemic, given the convenience and accessibility it offers.

In conclusion, the future of Tai Chi classes is one of synthesis - a blend of ancient wisdom with cutting-edge technology. While these emerging trends have the potential to revolutionize Tai Chi instruction and practice, the essence of Tai Chi - relaxation, mindfulness, and inner peace - must remain at its core. After all, it is this interweaving of mind, body, and spirit that has sustained Tai Chi's relevance across centuries. As we navigate this exciting phase of evolution in Tai Chi, it is imperative to ensure that technological advances enhance, rather than eclipse, its profound philosophical foundations.