An operation * is defined on the set, R, of real numbers by \(p * q = p + q + 2pq\). If the identity element is 0, find the value of p for which the operati...
An operation * is defined on the set, R, of real numbers by \(p * q = p + q + 2pq\). If the identity element is 0, find the value of p for which the operation has no inverse.
Answer Details
To find the value of p for which the operation has no inverse, we need to solve for the value of p that makes the equation \(p * q = q * p = 0\) have no solution for q other than q = 0.
Let's set up the equation:
\[p * q = q * p = p + q + 2pq\]
We want to find the value of p that makes the equation have no solution for q other than q = 0. So let's substitute q = 0:
\[p * 0 = 0 * p = p + 0 + 2p(0)\]
\[p = 0\]
Now, let's check if there is any other value of p that would make the equation have no solution for q other than q = 0. If p is not 0, we can rewrite the equation as:
\[q = \frac{-p}{2p + 1}\]
Now, if p is any value other than \(-\frac{1}{2}\), the denominator 2p+1 will not be zero, which means that there will always be a real number q that satisfies the equation. However, if p = \(-\frac{1}{2}\), the denominator becomes zero, which means that the equation has no solution for q other than q = 0.
Therefore, the value of p for which the operation has no inverse is \(-\frac{1}{2}\), and the answer is option A: \(\frac{-1}{2}\).