Engineering Mechanics - General Principles - Discussion

Discussion :: General Principles - General Questions (Q.No.1)

1. 

Solve the following equation for the two roots of x:   x2 — 16 = 0

[A]. x = 2i,   –2i
[B]. x = 4i,   –4i
[C]. x = 4,   –4
[D]. x = 2,   –2

Answer: Option C

Explanation:

No answer description available for this question.

Naveen said: (Dec 10, 2010)  
x^2-16=0
(x-4)*(x+4)=0
(x-4)=0 or (x+4)=0
x=4 , -4

Billa said: (Jan 28, 2011)  
x^2 - 16 = 0
x^2 = 16
x = sqrt(16)
x = 4 or -4

Prabu said: (Feb 25, 2011)  
Well Naveen you gave the exact method to find the ans.

Nishita said: (Apr 28, 2011)  
(x^2-16)=0
(x^2-4^2)=0
(x-4)(x+4)=0
therefore,
(x-4)=0,x=4
(x+4)=0,x=-4
hence,x=4,-4

Lakshmi said: (Jun 3, 2011)  
x^2 = 16

x = sqrt(16)

Therefore, x = +4 or -4.

Balajikumar said: (Jun 23, 2011)  
LAKSHMI Method is best one

Sri said: (Jul 8, 2011)  
Well billa's method is also good.

Kamal said: (Jul 16, 2011)  
Naveen is absolutely correct!!

Damodaran said: (Aug 13, 2011)  
Well the three methods are good.

Ashok said: (Aug 22, 2011)  
x^2-16=0
x^2=16
x=sq.root 16
i.e.x=+ or - 4
x=4;x=-4

Adil said: (Sep 5, 2011)  
(x)2-(4)2=0
(x-4)(x+4)=0
x-4=0,x+4=0
x=4,x=-4

Adil said: (Sep 5, 2011)  
Lakshmi I like your answer.

James said: (Sep 26, 2011)  
Laxmi's method is good.

Manik said: (Nov 2, 2011)  
Answer is correct.

Ashok.L.B.Naik said: (Feb 8, 2012)  
@Naveen's method is easy to solve.

Santhosh said: (Feb 24, 2012)  
Billa's method is easiest and understandable.

Pravi said: (Mar 8, 2012)  
Laxi method is easy.

Raja said: (May 23, 2012)  
Billa's method is very easy.

Murali said: (Jun 28, 2012)  
X^2-16=0.

X=sqrt (16).

X=4, -4.

Kamal said: (Sep 16, 2012)  
Why do use iota. Ioti (i) its value is also -1. That answer is also right option b.

Cherry said: (Sep 25, 2012)  
x^2 - 16 = 0
x^2 = 16
x = sqrt(16)
x = 4 or -4

Rakesh said: (Jan 31, 2015)  
(x)2-16 = 0.

We know that a2-b2 = (a+b)(a-b).

(x)2-(4)2 = 0.

(x+4)(x-4) = 0.

x = -4, +4.

Rupa said: (Jan 27, 2016)  
X^2 - 16 = 0.

X^2 = 16.

X = 4, -4.

Arun said: (Jul 22, 2016)  
Your method is easy to solve. @Naveen.

Winfred said: (Nov 13, 2016)  
@All, Nice solution thanks for it.

Darshan Dodia said: (Jul 5, 2017)  
According to Quadratic Equation ax^2+bx+c=0, roots of equation x = (-b+/-sqrt(b^2-4ac))/(2a).

Ajmal K said: (Nov 12, 2018)  
X^2-16=0.

X= +/-(√16),
X= +/-(4),
X=(+4) & x=(-4).

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