How do you graph # (x-1)(x+4)-y=0#?

Question

1655 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2018-02-01T19:13:19

Look below

#(x-1)(x+4)-y=0# can be simpified as

#x^2+3x-4=y#

now since we have a quadratic, label a, b, and c.

a=1
b=3
c=4 -- this is the y-intercept

now use the formula #(-b)/(2a)# to find the symmetrical line (which is imaginary)

#\frac{-3}{2(1)}#=#\frac{-3}{2}#

now use that to substitute x, which will be ur #y#

Btw, x is #-3/2#

now, #(\frac{-3}{2})^2+3(\frac{-3}{2})-4#

=#\frac{-25}{4}#

#(\frac{-3}{2}, \frac{-25}{4})#

GRAPH
graph{x^2+3x-4 [-9.29, 10.71, -8, 2]}

Your graph should look like that.