Question

TanA= 17/18, TanB =1/35 then Cos(A+B)



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Answer 1

Answer:

Step-by-step explanation:

tan(a+b)=tana+tanb/1-tanatanb

            =17/18+1/35/1-17/18*1/35

            =595+18/35*18-/18*35-17/18*35

            =613/630-17

            =613/613

            =1

tan(a+b)=1 therefore

a+b=45degree as tan45=1

similarly

cos(a+b)=cos45=1/sqrt2