sec2θ + cosec2θ = ?
A
cosec2θ
B
tan2θ
C
sec2θ. cosec2θ
D
tan2θ. cot2θ
উত্তরের বিবরণ
সমাধান:
sec2θ + cosec2θ
= (1/cos2θ) + (1/sin2θ)
= (sin2θ + cos2θ)/(cos2θ. sin2θ)
= 1/(cos2θ. sin2θ)
= (1/cos2θ). (1/sin2θ)
= sec2θ. cosec2θ
0
Updated: 1 month ago
1/{tanA√(1 - sin2A)} = ?
Created: 1 month ago
A
sinA
B
cosecA
C
tanA
D
secA
প্রশ্ন: 1/{tanA√(1 - sin2A)} = ?
সমাধান:
tanA√(1 - sin2A)
= tanA√(cos2A)
= (sinA/cosA) × cosA
= sinA
অতএব,
1/{tanA√(1 - sin2A)}
= 1/sinA
= cosecA
0
Updated: 1 month ago
cosA.sinA = 1 হয়, (cosA + sinA)2 = কত?
Created: 1 month ago
A
3
B
2
C
4
D
5
সমাধান:
(cosA + sinA)2
= cos2A + 2 cosA sinA + sin2A
= sin2A + cos2A + 2cosA.sinA
= 1 + 2 × 1 [∴ sin2A + cos2A = 1]
= 1 + 2
= 3
0
Updated: 1 month ago
sin(- 390°) এর মান কত?
Created: 1 month ago
A
√3/√2
B
√3/√2
C
1/√2
D
- 1/2
প্রশ্ন: sin(- 390°) এর মান কত?
সমাধান:
sin(- 390°)
= - sin390° [sin(- θ) = - sinθ]
= - sin(4 × 90° + 30°)
= - (sin30°)
= - sin30°
= - 1/2
0
Updated: 1 month ago
