Question

What it the x and y intercept of y=2x^2+3x+1

Answer 1

What you have here is a quadratic polynomial.

The form is: ax^2 + bx + c

C is ALWAYS the y-intercept in non-linear polynomials. So we immediately know the y-intercept to be 1.

For the X-intercept(s), we can solve in a few ways, but let's use the quadratic formula.

The quadratic formula states that y=-b+-((sqrt(b^2-4ac) / 2a).

A = 2

B = 3

C = 1

Plug in your information,

$\frac{-3 \frac{+}{-} \sqrt{3^2 - 4(2)(1)} }{2(2)} \\\sqrt{9 - 8}\\ \sqrt{1} \\\\\frac{-3 \frac{+}{-} 1}{4}$

y = (-3 +- 1) / 4

X = -.05

X = -1

Y = 1

X-Intercepts: -.05, -1

Y-Intercepts: 1