iOS device and smart TV

Yes.

3 possible ways:

1. Through Airplay 2 if your TV supports it: https://www.apple.com/apple-tv-app/devices/ (scroll down to the Airplay 2 enabled devices section and see if your Tv is one of them)
2. Airplaying to an Apple TV if you have one: https://support.apple.com/en-us/HT204289
3. Connecting the iPad directly to the TV using the digital av adapter and an HDMI cable. The av adapter type will depend on the model of iPad.

Yes, you should be able to and there are basically two methods to do so:

1. Via an Apple TV
2. Via an HDMI cable/Lightning AV Digital adapter directly from your iPad.

If your iPad is connected to TV using (a) an Apple Adapter appropriate to your iPad and an HDMI cable, or (b) via an AppleTV box - then yes, you can mirror your iPad display to a TV.