import math


def rise_pres(mach: float, beta:float, gamma=1.4) -> float:
    """

    Calculate rise in pressure after oblique shock

    Parameters
    ----------
    mach:float
        Mach number
    beta: float
        oblique shock angle
    gamma: float
        isentropic exponent

    Returns
    -------
    mach2: float
        Mach number after an oblique shock
    """
    m_sin_2 = mach * mach * math.sin(beta) * math.sin(beta)

    return (2.0 * gamma / (gamma + 1.0) * m_sin_2) - ((gamma-1.0) / (gamma + 1.0))