Răspuns :
[tex]tga=\dfrac{1}{ctga}=\dfrac12;\ \ tgb=\dfrac{1}{ctgb}=\dfrac15[/tex]
[tex]tg(a+b)=\dfrac{tga+tgb}{1-tga\cdot tgb}=\dfrac{\frac12+\frac15}{1-\frac12\frac15}=\dfrac79[/tex]
[tex]tg(a+b)=\dfrac{tga+tgb}{1-tga\cdot tgb}=\dfrac{\frac12+\frac15}{1-\frac12\frac15}=\dfrac79[/tex]
deci dupa acea formula rezultata anterior avem urmatoarea relatie de calcul :
ctg= 1 , tg=1
tg ctg
deci ⇒ tg a= 1 supra 2, iar de b = 1 supra 5 .
⇔ [tex] \frac{1}{2} + \frac{1}{5} = tg \frac{7}{10} [/tex]
ctg= 1 , tg=1
tg ctg
deci ⇒ tg a= 1 supra 2, iar de b = 1 supra 5 .
⇔ [tex] \frac{1}{2} + \frac{1}{5} = tg \frac{7}{10} [/tex]