For part (a) step one of induction is just T1=1 which is less than 3, step 2 your assumption is Tk<3 and then for step 3 you sub in Tk<3 into Tk+1=sqrt(3+2Tk) to get Tk+1>sqrt(3+6) and you can do the rest from there
Give the rest of the questions a go and send your working, itās not really productive to just be sent a solution