JAMIA 2021 — Mathematics PYQ
JAMIA | Mathematics | 2021Let f(t)=cost2sintsintamp;tamp;tamp;tamp;1amp;2tamp;t, then limt→0t2f(t) is equal to
Choose the correct answer:
- A.
0
(Correct Answer) - B.
1
- C.
2
- D.
3
0
Explanation
1. Define the Function f(t)
Assuming f(t) represents the determinant of the matrix:
2. Calculate the Determinant
We expand the determinant along the first row:
Now, evaluate each 2×2 minor:
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Minor 1: ttamp;2tamp;t=(t⋅t)−(2t⋅t)=t2−2t2=−t2
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Minor 2: 2sintsintamp;2tamp;t=(2sint⋅t)−(2t⋅sint)=2tsint−2tsint=0
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Minor 3: 2sintsintamp;tamp;t=(2sint⋅t)−(t⋅sint)=2tsint−tsint=tsint
Substitute these back into the expression for f(t):
3. Evaluate the Limit
We need to find limt→0t2f(t):
Split the fraction into two parts:
4. Apply Standard Limits
Using the standard limit limt→0tsint=1 and the fact that limt→0cost=1:
Final Result
The value of the limit is:
Explanation
1. Define the Function f(t)
Assuming f(t) represents the determinant of the matrix:
2. Calculate the Determinant
We expand the determinant along the first row:
Now, evaluate each 2×2 minor:
-
Minor 1: ttamp;2tamp;t=(t⋅t)−(2t⋅t)=t2−2t2=−t2
-
Minor 2: 2sintsintamp;2tamp;t=(2sint⋅t)−(2t⋅sint)=2tsint−2tsint=0
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Minor 3: 2sintsintamp;tamp;t=(2sint⋅t)−(t⋅sint)=2tsint−tsint=tsint
Substitute these back into the expression for f(t):
3. Evaluate the Limit
We need to find limt→0t2f(t):
Split the fraction into two parts:
4. Apply Standard Limits
Using the standard limit limt→0tsint=1 and the fact that limt→0cost=1:
Final Result
The value of the limit is:

