If the operation \( x \, ¤, y = 4x - y^2 \), and \( x, y \) are positive integers, which of the following cannot produce an odd value?
\( x \, ¤, y^2 \)
\( x \, ¤, 2y \)
\( y \, ¤, x \)
\( x \,¤, y \)
\( x \, ¤, (y+1) \)
Step 1: Formula is \( 4x - y^2 \).
Step 2: Check parities:
- If \( y \) is odd, \( y^2 \) odd, \( 4x - y^2 \) = even - odd = odd.
- If \( y \) is even, \( y^2 \) even, \( 4x - y^2 \) = even - even = even.
Step 3: For \( x \,¤, 2y \), we substitute \( y' = 2y \). Then term = \( 4x - (2y)^2 = 4x - 4y^2 = 4(x-y^2) \), always even.
Final Answer: \[ \boxed{x \,¤, 2y} \]
The relationship between two variables \( x \) and \( y \) is given by \( x + py + q = 0 \) and is shown in the figure. Find the values of \( p \) and \( q \). Note: The figure shown is representative.
