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The value of = sin 50° + cos70° -2tan² 225° is equal to sin 130° cos 110°
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- 1
- –2
- 2
- 0
- 1
Correct Option: B
| = | + | -2tan² 225° | ||
| sin 130° | cos 110° |
| = | + | - 2[tan (180° - 45°)]² | ||
| sin (180° - 50°) | cos (180° - 70°) |
| = | + | -2tan² 45° | ||
| sin 50°) | - cos 70°) |
∵ sin(180° – θ) = sinθ
cos(180° – θ) = – cosθ
tan(180° + θ) = tanθ
= 1 – 1 – 2 = –2
