Question

COS? (A-B) tcOS?B - 2 COSA COSB COS(AB,

JEE/Engineering Exams

Maths

Solution

4.0 (1 ratings)

Bol') ( cos ^{2}(A-B)+cos ^{2} B-2 cos A cos B cos ) ( =(cos A cos B+sin A sin B)^{2}+cos ^{2} B-frac{2 cos A cos B}{cos (A-B)} ) ( =cos ^{2} A cos ^{2} B+frac{sin ^{2} sin ^{2} B+2 sin A sin B cos A cos B}{+cos ^{2} B-2 cos A cos B} ) ( (cos A cos B+sin A sin B) ) ( cos ^{2} A cos ^{2} B+sin ^{2} A sin ^{2} B+2 sin A sin ^{2} ) ( cos A cos B+cos ^{4} ) ( -2 cos ^{2} A cos ^{2} B-2 cos A cos B sin A ) ( cos ^{2} A cos ^{2} B+sin ^{2} A sin ^{2} B+cos ^{2} B-2 cos ^{2} A cos ^{2} B ) ( -cos ^{2} A cos ^{2} B+sin ^{2} A sin ^{2} B+cos ^{2} B ) ( =0.008^{2} Bleft(1-cos ^{2} Aright)+sin ^{2} A sin ^{2} B ) ( =sin ^{2} B sin ^{2} A+sin ^{2} A sin ^{2} B ) ( =2(sin A sin B)^{2} )