Step by step explanations please, any graphs , formulas , definitions

Q4. A Giffen good... i. ...is by definition also a luxury good ii. ...has a positive income effect iii. ...has a positive substitution effect iv. ...has a larger income effect than a substitution effect Q5. The Engel curve for good X is upward sloping. What might be true? i. X could be an inferior good ii. X could be a normal good iii. X could be a luxury good iv. X could be a Giffen good