This is a Chemical Process Control question from the Chemical Engineering course. Please do not respond if you are not sure.

Applying the Routh-Hurwitz criterion, determine whether the following characteristic equations are stable, unstable, or marginally stable. In case there are unstable roots, say how many of the roots are contributing to the instability. a) S⁶ + 2s⁵ + 3s⁴ + 4s³ + 5s² + 6s + 7

b) s⁴ + 60s² + 600

c) -s³ - 10s² - 100s - 5

d) S⁶ + 9s⁵ + 32s⁴ + 74s³ + 136s² + 152s + 96