Find the upper limit for the zeros of the function
P(x) = 4x 4 + 8x 3 - 7x 2 - 21x - 9

We need to find the zeros.

4x^4 + 8x^3 - 7x^2 -21x - 9

You're supposed to use synthetic division, assuming you're in algebra 2. I removed my calculus work.

x = -1 1/2, 1+sqrt5/2  , 1-sqrt5/2

x= -1.5000000119775176

4x 4 + 8x 3 - 7x 2 - 21x - 9= 0

x= -0.618033988749895

4x 4 + 8x 3 - 7x 2 - 21x - 9= 0

x= 1.618033988749895

4x 4 + 8x 3 - 7x 2 - 21x - 9= 0

3x^3-x^2+6x-9

in geometry, parallel lines are lines in a plane which do not meet; that is, two lines in a plane that do not intersect or touch each other at any point are said to be parallel. by extension, a line and a plane, or two planes, in three-dimensional euclidean space that do not share a point are said to be parallel.