Solve the following inequalities
(i) |x 3 – 1| ≥ 1 – x
(ii)
≥ 1
(iii)
< 2
(iv)
> 0
(v) |x – 2| > |2x – 3|
(vi) |x + 2| + |x – 3| < |2x + 1|
Text Solution
Verified by ExpertsCHECK THE SOLUTION.
(i) |x 3 – 1| ≥ 1 – x ⇒ |(x – 1)| (x 2 + x + 1) ≥ 1 – x
Case - I x ≥ 1 ⇒ (x – 1) (x 2 + x + 1) + (x – 1) ≥ 0
(x – 1) (x 2 + x + 2) ≥ 0 ⇒ (x – 1) ≥ 0
x ≥ 1 ⇒ x ∈ [1, ∞ )
case - II x < 1
[– (x – 1) (x 2 + x + 1)] + (x – 1) ≥ 0 ⇒ – (x – 1) [x 2 + x + 1 – 1] ≥ 0
(x – 1) (x 2 + x) ≤ 0 = x (x – 1) (x + 1) ≤ 0 
x ∈ (– ∞ , –1] ∪ [0, 1)
Taking Union of both the cases, we get x ∈ (– ∞ , –1] ∪ [0, ∞ ) Ans.
(ii) |(x –2) 2 | ≥ 1 ⇒ (x – 2) 2 ≥ 1
(x – 2 + 1) (x – 2 – 1) ≥ 0 ⇒ (x – 1) (x – 3) ≥ 0
x ∈ (– ∞ , 1] ∪ [3, ∞ ) Ans.
(iii)
< 2
Case - I x ≤ –2 ⇒
– 2 < 0 ⇒
< 0
> 0 ⇒
> 0 i.e. x ∈
∪ (0, ∞ )
i.e. x ∈ (– ∞ , –2]
case - II x > –2
< 2 ⇒
–1 <0 ⇒
> 0
i.e. x ∈ (– ∞ , 0) ∪ (1, ∞ ) (Intersection with the given case )
i.e. x ∈ (–2, 0) ∪ (1, ∞ )
(iv)
> 0
Case - I x > 2
Case - II x < 2
x ∈ (2, ∞ ) – 1 > 0 Not possible l
x ∈ (2, ∞ ) Ans.
(v) Squaring
x 2 – 4x + 4 > 4x 2 – 12x + 9
3x 2 – 8x + 5 < 0 ⇒ (x – 1)(3x – 5) < 0 ⇒ x ∈ 
(vi) case - I : x < –2
–x – 2 – x + 3 < –2x – 1 ⇒ 1 < –1 Not possible
Case - II : –2 ≤ x < 
x + 2 – x + 3 < – 2x – 1 ⇒ 2x < –6 ⇒ x < –3 Not possible
case-III :
≤ x < 3
x + 2 – x + 3 < 2x + 1 ⇒ x > 2
case -IV : x ≥ 3
x + 2 + x – 3 < 2x + 1 ⇒ 1 > –1 Hence x ∈ (2, ∞ )
──────────────────────────────────────────────────────────────────────────────────────────
Prepare Smarter with CGP Edu
Get practice questions, solutions, and test series in one place.
Write a Review
Share your experience with this question and solution.
Commentary
Send your comment, doubt, correction, or feedback to admin.
Similar Questions
Explore conceptually related problems