Bra-ket notation is concise and useful.
A wavefunction is represented by a ket \(|\psi\rangle\).
The complex conjugate of wave function is written as a bra \(\langle\psi|\).
The complex conjugate of a variable is found by swapping the sign of the imaginary part of said variable’s complex number, in other words: reflecting z across the real axis. For example,
\\(z = x + iy\\)
\\(z^* = x – iy\\)
A bra on the left and a ket on the right implies integration over dt.
\\(\langle\psi|\psi\rangle \equiv \int\psi^*\psi dt\\)
Similarly
\\(\langle\psi|\hat{X}|\psi\rangle \equiv \int\psi^*\hat{X}\psi dt\\)
My brief tutorial covered the basic usages of bra-ket notation in a quantum mechanical context; bra-ket notation is also used elsewhere.