Question

tanA+tanB/tan(A+B) + tanA-tanB/tan(A-B)​

Answer 1

tanA+tanB = (sinA/cosA)+(sinB/cosB)

= (sinAcosB + sinBcosA)/(cosAcosB)

= (Sin(A+B))/(cosAcosB)

Therefore

tanA+tanB = (sin(A+B))/(cosAcosB)

Or

we know that

tan(A+B) = (tanA + tanB) /(1-tanAtanB)

tanA+tanB = tan(A+B)(1-tanAtanB)