If you need to preserve battery life, maybe because you are doing image analysis on the go then sacrificing graphics performance for the duration of the session may be an acceptable compromise, but you may also choose to run the application with the dedicated GPU on other occasions. You can specify which GPU to use on launching the application by right-clicking on the application icon and choosing the Run with graphics processor option:

You can then choose with GPU to use as needed and the application will launch.

But it is also possible to permanently set a preference for wich GPU to use that that the application will automatically select a specific GPU on launch unless specified otherwise as above.