Chapter 3.4, Problem 107E

To determine

(a)

To prove:

That the cubic equation $x^3+a{x}^2+bx+c=0$ can be turned in depressed cubic $X^3+pX+q=0$ if $x$ replaces by $X-\frac{a}{3}$.

To determine

(b)

To find:

The depressed equation of the cubic equation $x^3+6x^2+9x+4=0$ if the term $x$ is replacedby $X-\frac{a}{3}$.