What is a temporal dead zone and how does it apply here? Javascript

Indicate the line numbers for each identifer's temporal dead zone 1 main(); 2 console.log("beginning"); 3 function main)( 4 console.log("in main") let result; let p foo(15); 7 function foo(x) 6 console.log("in foo") let r 3.3 let t-r**2+ x; if(x