Menu Close

Solve-2-x-2-x-1-lt-1-




Question Number 16519 by tawa tawa last updated on 23/Jun/17
Solve:  ∣2 − x∣ − 2 ∣x + 1∣ < 1
Solve:2x2x+1<1
Answered by ajfour last updated on 23/Jun/17
Commented by ajfour last updated on 23/Jun/17
∣2−x∣−2∣x+1∣<1  whenever y=∣2−x∣ is below   y= 2∣x+1∣+1   this occurs for x<x_1  (see graph)   and  x>x_2   to obtain x_1 (wbich is <−1):   2−x_1  = 1−2(x_1 +1)   x_1 = −3   to obtain x_2   (−1<x_2  <2)   2−x_2  = 1+2(x_2 +1)   3x_2 = −1  ⇒   x_2  = −1/3    so, for given condition to  remain true             x ∉ [−3, ((−1)/3)]     that is x∈ (−∞, −3)∪(((−1)/3), ∞).
2x2x+1∣<1whenevery=∣2xisbelowy=2x+1+1thisoccursforx<x1(seegraph)andx>x2toobtainx1(wbichis<1):2x1=12(x1+1)x1=3toobtainx2(1<x2<2)2x2=1+2(x2+1)3x2=1x2=1/3so,forgivenconditiontoremaintruex[3,13]thatisx(,3)(13,).
Commented by tawa tawa last updated on 23/Jun/17
God bless you sir. i really appreciate.
Godblessyousir.ireallyappreciate.
Answered by b.e.h.i.8.3.4.1.7@gmail.com last updated on 24/Jun/17
1)x≥2⇒−(2−x)−2(x+1)<1⇒  −x−4<1⇒−x<−5⇒x>5⇒x∈[5,∞)  2) −1≤x<2⇒2−x−2(x+1)<1⇒  −3x<1⇒x>−(1/3)⇒x∈[−(1/3),2)  ⇒x∈[−(1/3),2)∪[5,∞).
1)x2(2x)2(x+1)<1x4<1x<5x>5x[5,)2)1x<22x2(x+1)<13x<1x>13x[13,2)x[13,2)[5,).
Commented by tawa tawa last updated on 24/Jun/17
God bless you sir.
Godblessyousir.
Commented by ajfour last updated on 24/Jun/17
if x=3 >2   ∣2−x∣= 1    2∣x+1∣=8    ∣2−x∣−2∣x+1∣=−7 <1  if  x=−4    ∣2−x∣= 6   2∣x+1∣ = 6  ∣2−x∣−2∣x+1∣=0 < 1   if x→−∞   ∣2−x∣−2∣x+1∣= 2−x+2(x+1)                  = x+4  = −∞+4 <1
ifx=3>22x∣=12x+1∣=82x2x+1∣=7<1ifx=42x∣=62x+1=62x2x+1∣=0<1ifx2x2x+1∣=2x+2(x+1)=x+4=+4<1
Commented by tawa tawa last updated on 24/Jun/17
God bless you sir.
Godblessyousir.

Leave a Reply

Your email address will not be published. Required fields are marked *