since y = –1.5x² its domain is R=] -infinity, infinity[
the inverse of y
–1/1.5 y = x² , and x = sqrt ((–1/1.5) y) , and f^-1 (x) = sqrt ((–1/1.5) x)
its domain is –1/1.5) x>=0, so x<=0,
from where, the range of y = –1.5x² is the interval ]-infinity, 0]
