find all the zeros of the equation -3x^4+27x^2+1200=0
4 answers
PLZ is a school subject I've never heard of. I don't think any of the tutors here have studied or can teach that subject.
pre cal
I think they named it "PLZ" because they wanted someone to please help them. My understanding is that "PLZ" translates to please.
let z = x^2
then you have
3 z^2 -27 z -1200 = 0
or
z^2 - 9 z - 1200 = 0
z is about 40 or -30
(you can do quadratic accurately)
so
x = +sqrt 40 or - sqrt 40 or +i sqrt 30 or -i sqrt 30
then you have
3 z^2 -27 z -1200 = 0
or
z^2 - 9 z - 1200 = 0
z is about 40 or -30
(you can do quadratic accurately)
so
x = +sqrt 40 or - sqrt 40 or +i sqrt 30 or -i sqrt 30
2 answers