Rewrite … as …, with … and … ______

Rewrite $cy-b{y}^2$ as $a^2-x^2$, with $x=\sqrt{b}y-c/2\sqrt{b}$ and $a=$ ______ . Substitute for $a$ and $x$ in the integral taken from tables, to obtain the $y$-integral in the text:
$$\int \frac{dx}{a^2-x^2}=\frac{1}{2a}\ln \frac{a+x}{a-x}\int \frac{dy}{cy-b{y}^2}=\frac{1}{c}\ln \frac{y}{c-by}$$

Gilbert Strang, Calculus, 3rd edition (Wellesley-Cambridge Press; MIT OpenCourseWare RES.18-001) · §6.5 Separable Equations Including the Logistic Equation, #36