Engineering Mechanics - General Principles - Discussion

Discussion Forum : General Principles - General Questions (Q.No. 1)
1.
Solve the following equation for the two roots of x:   x2 — 16 = 0
x = 2i,   –2i
x = 4i,   –4i
x = 4,   –4
x = 2,   –2
Answer: Option
Explanation:
No answer description is available. Let's discuss.
Discussion:
27 comments Page 1 of 3.

Darshan Dodia said:   8 years ago
According to Quadratic Equation ax^2+bx+c=0, roots of equation x = (-b+/-sqrt(b^2-4ac))/(2a).
(1)

Rakesh said:   1 decade ago
(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.

Nishita said:   1 decade ago
(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

Kamal said:   1 decade ago
Why do use iota. Ioti (i) its value is also -1. That answer is also right option b.

Ajmal k said:   7 years ago
X^2-16=0.

X= +/-(√16),
X= +/-(4),
X=(+4) & x=(-4).
(1)

Prabu said:   1 decade ago
Well Naveen you gave the exact method to find the ans.

Naveen said:   1 decade ago
x^2-16=0
(x-4)*(x+4)=0
(x-4)=0 or (x+4)=0
x=4 , -4

ASHOK said:   1 decade ago
x^2-16=0
x^2=16
x=sq.root 16
i.e.x=+ or - 4
x=4;x=-4

Lakshmi said:   1 decade ago
x^2 = 16

x = sqrt(16)

Therefore, x = +4 or -4.

Billa said:   1 decade ago
x^2 - 16 = 0
x^2 = 16
x = sqrt(16)
x = 4 or -4


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