CUET PG 2023 — Mathematics PYQ
CUET PG | Mathematics | 2023If cot² 45°-sin² 45° = K sin² 30° x tan² 45° x sec² 45, then the value of K is
Choose the correct answer:
- A.
0
- B.
1
(Correct Answer) - C.
3
- D.
4
1
Explanation
1. Identify the Trigonometric Values
First, let's plug in the standard values for the trigonometric ratios:
-
cot45∘=1
-
sin45∘=21
-
sin30∘=21
-
tan45∘=1
-
sec45∘=2
2. Solve the Left Hand Side (LHS)
LHS=cot245∘−sin245∘
LHS=(1)2−(21)2
LHS=1−21
LHS=21
3. Solve the Right Hand Side (RHS)
RHS=K⋅sin230∘⋅tan245∘⋅sec245∘
RHS=K⋅(21)2⋅(1)2⋅(2)2
RHS=K⋅41⋅1⋅2
RHS=K⋅42
RHS=K⋅21
4. Find the value of K
Equating LHS and RHS:
21=K⋅21
Divide both sides by 21:
K=1
The value of K is 1.
Explanation
1. Identify the Trigonometric Values
First, let's plug in the standard values for the trigonometric ratios:
-
cot45∘=1
-
sin45∘=21
-
sin30∘=21
-
tan45∘=1
-
sec45∘=2
2. Solve the Left Hand Side (LHS)
LHS=cot245∘−sin245∘
LHS=(1)2−(21)2
LHS=1−21
LHS=21
3. Solve the Right Hand Side (RHS)
RHS=K⋅sin230∘⋅tan245∘⋅sec245∘
RHS=K⋅(21)2⋅(1)2⋅(2)2
RHS=K⋅41⋅1⋅2
RHS=K⋅42
RHS=K⋅21
4. Find the value of K
Equating LHS and RHS:
21=K⋅21
Divide both sides by 21:
K=1
The value of K is 1.

