The functions f\mathrm{f} and g\mathrm{g} are defined by f:x↦x2+2x2x2−5x+2,x∈R+, x≠12,2,g:x↦−32x2−5x+2,x∈R+, x≠12,2.\begin{aligned} \mathrm{f} : x &\mapsto \frac{x^2 + 2x}{2x^2 - 5x + 2}, \quad x \in \mathbb{R}^+, \ x \ne \frac{1}{2}, 2, \\ \mathrm{g} : x &\mapsto \frac{-3}{2x^2 - 5x + 2}, \quad x \in \mathbb{R}^+, \ x \ne \frac{1}{2}, 2. \end{aligned} Without the use of the graphic calculator, find the subset of the domain for which the value of f(x)\mathrm{f}(x) is greater than or equal to the value of g(x)\mathrm{g}(x).

Work through it with AI →

It won't just hand you the answer — it asks where you're stuck.How the checker works

Worked solution

2

1. Set up the rational inequality $\mathrm{f}(x) \ge \mathrm{g}(x)$ and combine terms into a single fraction.

x2+2x2x2−5x+2≥−32x2−5x+2\frac{x^2 + 2x}{2x^2 - 5x + 2} \ge \frac{-3}{2x^2 - 5x + 2}
x2+2x+32x2−5x+2≥0\frac{x^2 + 2x + 3}{2x^2 - 5x + 2} \ge 0

2. Analyse the numerator to determine its sign.

Completing the square for the numerator:
x2+2x+3=(x+1)2+2x^2 + 2x + 3 = (x+1)^2 + 2
Since (x+1)2≥0(x+1)^2 \ge 0 for all real xx, the numerator x2+2x+3>0x^2 + 2x + 3 > 0 for all real xx.

3. Formulate and solve the corresponding inequality for the denominator.

Since the numerator is strictly positive, the overall fraction is ≥0\ge 0 if and only if the denominator is strictly positive (it cannot be zero):
2x2−5x+2>02x^2 - 5x + 2 > 0
(2x−1)(x−2)>0(2x - 1)(x - 2) > 0
Solving this quadratic inequality gives:
x<12orx>2x < \frac{1}{2} \quad \text{or} \quad x > 2

4. Determine the final subset by intersecting the inequality solution with the given domain.

The function's domain is x∈R+,x≠12,2x \in \mathbb{R}^+, x \ne \frac{1}{2}, 2, which means x>0x > 0.
Intersecting x<12 or x>2x < \frac{1}{2} \text{ or } x > 2 with x>0x > 0 gives:
0<x<12orx>20 < x < \frac{1}{2} \quad \text{or} \quad x > 2
This gives the required subset of the domain.

Answer

(0,12)∪(2,∞)(0, \frac{1}{2}) \cup (2, \infty)

AI analysis — may contain mistakes.

Worked this one out on paper? Snap your steps and Gigle's AI math checker will circle the step where it went wrong.

More questions on this topic

  1. 1The sum of the first nn terms of a series is given by Sn=3n(n+2)S_n = 3n(n + 2). Show that this series follows an arithmetic pr…
  2. 2The sum of the first nn terms of a series is given by Sn=3n(n+2)S_n = 3n(n + 2). Show that this series follows an arithmetic pr…
  3. 3Find the exact solution of the inequality 2x+1x2−1≤1.\frac{2x+1}{x^2-1} \le 1. A curve GG has equation ay2+bx3+cx=2ay^2 + bx^3 + cx = 2, w…
  4. 4The curve CC has equation y=x−2kx2+x−2y = \frac{x - 2}{kx^2 + x - 2}, where k>1k > 1. Find the equation of the tangent at the poin…
  5. 5The function gg is defined by g:x↦ln⁡(x−3)g : x \mapsto \ln(x - \sqrt{3}), for x∈Rx \in \mathbb{R}, x>3x > \sqrt{3}. Explain how yo…