Solve a problem of your own!
Download the Studdy App!

Math

Math Snap

PROBLEM

f(x)=3x2+2x+3f(x)=-3 x^{2}+2 x+3 Round to the nearest hundredth if necessary.
If there is more than one xx-intercept, separate them If applicable, click on "None".
\begin{tabular}{|ll|} \hline vertex: & (II, \square \\ xx-intercept(s): & \square \\ \hline \end{tabular}

STEP 1

1. The function given is a quadratic function of the form f(x)=ax2+bx+c f(x) = ax^2 + bx + c .
2. The vertex of a quadratic function in standard form can be found using the formula x=b2a x = -\frac{b}{2a} .
3. The x x -intercepts (roots) of the quadratic function can be found using the quadratic formula x=b±b24ac2a x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} .

STEP 2

1. Identify the coefficients a a , b b , and c c .
2. Calculate the vertex of the quadratic function.
3. Calculate the x x -intercepts using the quadratic formula.

STEP 3

Identify the coefficients from the quadratic function f(x)=3x2+2x+3 f(x) = -3x^2 + 2x + 3 .
Here, a=3 a = -3 , b=2 b = 2 , and c=3 c = 3 .

STEP 4

Calculate the x x -coordinate of the vertex using the formula x=b2a x = -\frac{b}{2a} .
x=22(3)=26=13 x = -\frac{2}{2(-3)} = \frac{-2}{-6} = \frac{1}{3}

STEP 5

Substitute x=13 x = \frac{1}{3} into the function to find the y y -coordinate of the vertex.
f(13)=3(13)2+2(13)+3 f\left(\frac{1}{3}\right) = -3\left(\frac{1}{3}\right)^2 + 2\left(\frac{1}{3}\right) + 3 =3(19)+23+3 = -3\left(\frac{1}{9}\right) + \frac{2}{3} + 3 =13+23+3 = -\frac{1}{3} + \frac{2}{3} + 3 =13+3 = \frac{1}{3} + 3 =13+93 = \frac{1}{3} + \frac{9}{3} =103 = \frac{10}{3} The vertex is (13,103) \left(\frac{1}{3}, \frac{10}{3}\right) .

STEP 6

Calculate the x x -intercepts using the quadratic formula x=b±b24ac2a x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} .
First, calculate the discriminant:
b24ac=224(3)(3) b^2 - 4ac = 2^2 - 4(-3)(3) =4+36 = 4 + 36 =40 = 40

SOLUTION

Substitute the discriminant into the quadratic formula:
x=2±402(3) x = \frac{-2 \pm \sqrt{40}}{2(-3)} =2±406 = \frac{-2 \pm \sqrt{40}}{-6} Simplify 40 \sqrt{40} :
40=4×10=210 \sqrt{40} = \sqrt{4 \times 10} = 2\sqrt{10} x=2±2106 x = \frac{-2 \pm 2\sqrt{10}}{-6} =26±2106 = \frac{-2}{-6} \pm \frac{2\sqrt{10}}{-6} =13103 = \frac{1}{3} \mp \frac{\sqrt{10}}{3} The x x -intercepts are:
x=1+103andx=1103 x = \frac{1 + \sqrt{10}}{3} \quad \text{and} \quad x = \frac{1 - \sqrt{10}}{3} Calculate these values to the nearest hundredth:
x1+3.1634.1631.39 x \approx \frac{1 + 3.16}{3} \approx \frac{4.16}{3} \approx 1.39 x13.1632.1630.72 x \approx \frac{1 - 3.16}{3} \approx \frac{-2.16}{3} \approx -0.72 The vertex is (13,103)(0.33,3.33) \left(\frac{1}{3}, \frac{10}{3}\right) \approx (0.33, 3.33) .
The x x -intercepts are approximately 1.39 1.39 and 0.72 -0.72 .

Was this helpful?
banner

Start understanding anything

Get started now for free.

OverviewParentsContactPolicyTerms
TwitterInstagramFacebookTikTokDiscord