CUET Preparation Today
Find the value of sin73° + cos137° |
sin13° cos13° cos18° sin18° |
sin13° |
sin73° + cos137° [(cos90°+θ) = -sinθ] = sin73° + (-sin47°) [sin(c-d) = 2cos\(\frac{c+d}{2}\) × sin\(\frac{c - d}{2}\)] ⇒ 2cos(\(\frac{73+47}{2}\)) × sin(\(\frac{73 - 47}{2}\)) 2 × cos60° × sin13° 2 × \(\frac{1}{2}\) × sin13° = sin13° |
