How do you find the x and y intercepts for y=2x^2-4x+3y=2x24x+3?

2 Answers
Nov 13, 2015

y-intercept =3=3
There are no x-intercepts

Explanation:

Given y=2x^2-4x+3y=2x24x+3

The y-intercept is the value of yy when x=0x=0
color(white)("XXX")y=2(0)^2-4(0)+3 = 3XXXy=2(0)24(0)+3=3

For a quadratic in the general form:
color(white)("XXX")y=ax^2+bx+cXXXy=ax2+bx+c
the determinant Delta = b^2-4ac indicates the number of zeros.

Delta {(< 0, rArr, "no solutions"),(=0, rArr, "one solution"),(>0,rArr,"two solutions"):}

In this case
color(white)("XXX")Delta = (-4)^2-4(2)(3) < 0
so there are no solutions (i.e. no values for which the expression is equal to zero).

This can also be seen from a graph of this equation:
graph{2x^2-4x+3 [-6.66, 13.34, -0.64, 9.36]}

Nov 13, 2015

(0, 3)

Explanation:

x = 0 \Rightarrow y = 0 - 0 + 3

y = 0 \Rightarrow x = frac{-b ± sqrt {b^2 - 4ac}}{2a}

a = 2, b = -4, c = 3

But Delta < 0, then there is no real root (x_0, 0).