Basically, you can use a 43-inch TV as a monitor. Almost all 43-inch TVs have an HTML or DIV connection. This means you can easily connect your computer to the TV.
If the TV has a Smart TV function, you can also log on to the network directly from your computer.
Of course, the recommended minimum distance is 1.60 metres for 4K and 2.70 metres for Full HD. If you sit too close, you can get eye problems.