Question

if Sin A-4/5 and Sin B = 5/13,
then Cos (A+B) =​

Answer 1

Step-by-step explanation:

COS(A+B)=cosA. cosB-sinA.sinB

=cosA.cosB-4/5(5/13)

=cosA. cosB-4/13

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Answer 2

Answer:cos (A+B)=16/65

Step-by-step explanation:

Using Pythagoras theory and the idea of "SOH,CAH, TOA "

cosA=3/5 cosB=12/13

Cos(A+B)=cosAcosB-singing

Cos (A+B)=(3/5)(12/13)-(4/5)(5/13)

=36/65-20/65

=16/65