We read your photo as:

Given the function f(x) = x2 − 2x − 3, determine its range, x-intercepts (D and E), and the equation of line g passing through P and E.

Mathematics

ScanSolve AI Answer

Answers

5 parts
6.1

y≥−4y \ge -4

6.2

D(-1; 0), E(3; 0)

6.3

g(x)=x−3g(x) = x-3

6.4

x<0 or x>3x < 0 \text{ or } x > 3

6.5
6.25
Graph of f(x) = x² − 2x − 3

Use the left and right arrow keys to trace the curve, up and down to jump between key points, and plus and minus to zoom.

Key points of f(x) = x² − 2x − 3
Pointxy
x-intercept−10
y-intercept0−3
Minimum1−4
x-intercept30

Step-by-step solution

18 steps

Here are the solutions to the problems:

Part 6.1

The function f(x)=x2−2x−3f(x) = x^2 - 2x - 3 is a parabola opening upwards, as the coefficient of x2x^2 is positive. The turning point is given as T(1;−4)T(1; -4). The range of ff is all possible y-values. Since the parabola opens upwards, the minimum y-value is the y-coordinate of the turning point.
The range of ff is y≥−4y \ge -4.

y≥−4\boxed{y \ge -4}

Part 6.2D(-1; 0), E(3; 0)

D and E are the x-intercepts of f(x)f(x). To find the x-intercepts, we set f(x)=0f(x) = 0.

x2−2x−3=0x^2 - 2x - 3 = 0
  1. Factor the quadratic equation.

    (x−3)(x+1)=0(x-3)(x+1) = 0
  2. Solve for xx.

    x−3=0orx+1=0x-3=0 \quad \text{or} \quad x+1=0 x=3orx=−1x=3 \quad \text{or} \quad x=-1
  3. Assign the coordinates based on the graph.

    From the graph, D is the negative x-intercept and E is the positive x-intercept.
    The coordinates are D(−1;0)D(-1; 0) and E(3;0)E(3; 0).

    D(−1;0),E(3;0)\boxed{D(-1; 0), E(3; 0)}

Part 6.3

g(x)=x−3g(x) = x-3

The equation of gg is a straight line g(x)=mx+cg(x) = mx+c. The graphs of ff and gg intersect at P and E.

  1. Find the coordinates of P.

    P is the y-intercept of f(x)f(x). To find P, set x=0x=0 in f(x)f(x).

    f(0)=(0)2−2(0)−3=−3f(0) = (0)^2 - 2(0) - 3 = -3

    So, P is (0;−3)(0; -3).

  2. Use the coordinates of P and E to find the equation of g(x)g(x).

    The line g(x)g(x) passes through P(0;−3)P(0; -3) and E(3;0)E(3; 0).
    The y-intercept cc is the y-coordinate of P, so c=−3c = -3.

  3. Calculate the slope mm.

    m=y2−y1x2−x1=0−(−3)3−0=33=1m = \frac{y_2 - y_1}{x_2 - x_1} = \frac{0 - (-3)}{3 - 0} = \frac{3}{3} = 1
  4. Write the equation of g(x)g(x).

    g(x)=1x−3g(x) = 1x - 3 g(x)=x−3\boxed{g(x) = x-3}

Part 6.4

x<0 or x>3x < 0 \text{ or } x > 3

We need to find the values of xx for which f(x)−g(x)>0f(x) - g(x) > 0, which means f(x)>g(x)f(x) > g(x).
This inequality holds when the graph of f(x)f(x) is above the graph of g(x)g(x).

  1. Identify the intersection points of f(x)f(x) and g(x)g(x).

    The graphs intersect at P(0;−3)(0; -3) and E(3;0)(3; 0). These are the points where f(x)=g(x)f(x) = g(x).

  2. Observe the graph to determine where f(x)f(x) is above g(x)g(x).

    From the graph, f(x)f(x) is above g(x)g(x) for xx-values to the left of P and to the right of E.
    So, x<0x < 0 or x>3x > 3.

    x<0 or x>3\boxed{x < 0 \text{ or } x > 3}

Part 6.56.25

We need to determine the maximum vertical distance between h(x)h(x) and g(x)g(x) for x∈[−2;3]x \in [-2; 3], where h(x)=−f(x)h(x) = -f(x).

  1. Find the equation for h(x)h(x).

    h(x)=−f(x)=−(x2−2x−3)=−x2+2x+3h(x) = -f(x) = -(x^2 - 2x - 3) = -x^2 + 2x + 3
  2. Define the vertical distance function D(x)D(x).

    The vertical distance is D(x)=∣h(x)−g(x)∣D(x) = |h(x) - g(x)|.

    D(x)=∣(−x2+2x+3)−(x−3)∣D(x) = |(-x^2 + 2x + 3) - (x-3)| D(x)=∣−x2+2x+3−x+3∣D(x) = |-x^2 + 2x + 3 - x + 3| D(x)=∣−x2+x+6∣D(x) = |-x^2 + x + 6|
  3. Find the maximum value of the expression inside the absolute value, k(x)=−x2+x+6k(x) = -x^2 + x + 6, on the interval x∈[−2;3]x \in [-2; 3].

    This is a downward-opening parabola. Its maximum value occurs at its vertex.
    The x-coordinate of the vertex is x=−b2a=−12(−1)=12x = -\frac{b}{2a} = -\frac{1}{2(-1)} = \frac{1}{2}.
    The y-coordinate of the vertex is k(12)=−(12)2+(12)+6=−14+24+244=254=6.25k\left(\frac{1}{2}\right) = -\left(\frac{1}{2}\right)^2 + \left(\frac{1}{2}\right) + 6 = -\frac{1}{4} + \frac{2}{4} + \frac{24}{4} = \frac{25}{4} = 6.25.
    Since x=12x=\frac{1}{2} is within the interval [−2;3][-2; 3], the maximum value of k(x)k(x) is 6.25.

  4. Check the values at the endpoints of the interval.

    At x=−2x=-2: k(−2)=−(−2)2+(−2)+6=−4−2+6=0k(-2) = -(-2)^2 + (-2) + 6 = -4 - 2 + 6 = 0.
    At x=3x=3: k(3)=−(3)2+(3)+6=−9+3+6=0k(3) = -(3)^2 + (3) + 6 = -9 + 3 + 6 = 0.

  5. Determine the maximum vertical distance.

    The maximum value of k(x)k(x) is 6.25, and since k(x)k(x) is positive on the interval (−2,3)(-2, 3), D(x)=k(x)D(x) = k(x).
    The maximum vertical distance is 6.25.

    6.25\boxed{6.25}

Part 6.6· 4 steps

Given k(x)=g(x)−nk(x) = g(x) - n. We need to determine nn if k(x)k(x) is a tangent to f(x)f(x).

  1. Write the equation for k(x)k(x).

    k(x)=(x−3)−n=x−3−nk(x) = (x-3) - n = x - 3 - n
  2. Find the derivatives of f(x)f(x) and k(x)k(x).

    f(x)=x2−2x−3  ⟹  f′(x)=2x−2f(x) = x^2 - 2x - 3 \implies f'(x) = 2x - 2 k(x)=x−3−n  ⟹  k′(x)=1k(x) = x - 3 - n \implies k'(x) = 1
  3. For k(x)k(x) to be tangent to f(x)f(x), their slopes must be equal at the point of tangency.

    f′(x)=k′(x)f'(x) = k'(x) 2x−2=12x - 2 = 1 2x=32x = 3 x=32x = \frac{3}{2}

    This is the x-coordinate of the point of tangency.

  4. At the point of tangency, the y-values of f(x)f(x) and k(x)k(x) must be equal.

    f(32)=k(32)f\left(\frac{3}{2}\right) = k\left(\frac{3}{2}\right)

    Substitute $x = \

Was this helpful?

Try one yourself

A new problem that tests the same skill.

Still stuck on this one?

Ask a follow-up, and the answer starts from this question.

Got a different question?Ask your own question
Handwritten step-by-step solution preview

Handwritten Step-by-Step Solution

Get this as a handwritten image on WhatsApp — like a tutor wrote it for you.

Try on WhatsApp