KeerthanaPosted on यदि cosC – cosD = y, तो y का मूल्य है a2sin(C+D2)⋅sin(C−D2)2 sin left(frac{mathrm{C}+mathrm{D}}{2} ight) cdot sin left(frac{mathrm{C}-mathrm{D}}{2} ight)2sin(2C+D)⋅sin(2C−D) b−2cos(C+D2)⋅cos(C−D2)-2 cos left(frac{mathrm{C}+mathrm{D}}{2} ight) cdot cos left(frac{mathrm{C}-mathrm{D}}{2} ight)−2cos(2C+D)⋅cos(2C−D) c2cos(C+D2)⋅cos(C−D2)2 cos left(frac{mathrm{C}+mathrm{D}}{2} ight) cdot cos left(frac{mathrm{C}-mathrm{D}}{2} ight)2cos(2C+D)⋅cos(2C−D) d−2sin(C+D2)⋅sin(C−D2)-2 sin left(frac{mathrm{C}+mathrm{D}}{2} ight) cdot sin left(frac{mathrm{C}-mathrm{D}}{2} ight)−2sin(2C+D)⋅sin(2C−D) Answer : Option DExplanation : यहाँ, cosC – cosD = y ⇒y=cosC−cosDRightarrow y=cos mathrm{C}-cos mathrm{D}⇒y=cosC−cosD ⇒y=−2sinRightarrow y=-2 sin⇒y=−2sin (C+D2)⋅sin(C−D2)left(frac{mathrm{C}+mathrm{D}}{2} ight) cdot sin left(frac{mathrm{C}-mathrm{D}}{2} ight)(2C+D)⋅sin(2C−D) [∵quad[ecause[∵ यह cosC−cosD]cos mathrm{C}-cos mathrm{D}]cosC−cosD] का मूल सूत्र है Rate This:NaN / 5 - 1 votesAdd comment
