JAMIA 2026 — Mathematics PYQ
JAMIA | Mathematics | 2026If A=[02amp;xamp;0] and ∣A2∣=100, then value of x is:
Choose the correct answer:
- A.
±2
- B.
±3
- C.
±4
- D.
±5
(Correct Answer)
±5
Explanation
Step 1: Find the determinant of matrix A
Given the matrix:
A=[02amp;xamp;0]
The determinant ∣A∣ is calculated as:
∣A∣=(0×0)−(x×2)
∣A∣=0−2x=−2x
Step 2: Apply the determinant property
We are given that ∣A2∣=100. Using the property ∣A2∣=∣A∣2, we can write:
(∣A∣)2=100
Substitute the value of ∣A∣=−2x into the equation:
(−2x)2=100
4x2=100
Step 3: Solve for x
Divide both sides by 4:
x2=4100
x2=25
Taking the square root on both sides gives:
x=±25
x=±5
Correct Answer:
(d) ±5
Explanation
Step 1: Find the determinant of matrix A
Given the matrix:
A=[02amp;xamp;0]
The determinant ∣A∣ is calculated as:
∣A∣=(0×0)−(x×2)
∣A∣=0−2x=−2x
Step 2: Apply the determinant property
We are given that ∣A2∣=100. Using the property ∣A2∣=∣A∣2, we can write:
(∣A∣)2=100
Substitute the value of ∣A∣=−2x into the equation:
(−2x)2=100
4x2=100
Step 3: Solve for x
Divide both sides by 4:
x2=4100
x2=25
Taking the square root on both sides gives:
x=±25
x=±5
Correct Answer:
(d) ±5
