Question 858183
Use the angle sum formulas for sine and cosine to write tan(μ+ϑ) in terms of sin(μ), sin(ϑ),cos(μ)and cos(ϑ)
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sin(u+ϑ)=sinu*cosϑ+cosu*sinϑ
cos(u+ϑ)=cosu*cosϑ-sinu*sinϑ
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tan(u+ϑ)=sin(u+ϑ)/cos(u+ϑ)=(sinu*cosϑ+cosu*sinϑ)/(cosu*cosϑ-sinu*sinϑ)