[{tan(alpha)/(2)tan((pi)/(4)-8/2)}=tan((1-tan beta)/(cos alpha+cos alpha))],[(1)/(tan tan2(pi)/(2)))=1]

Prove that 2tan^(-1)[tan((alpha)/(2)) tan((pi)/(4)-(beta)/(2))]=tan^(-1)((sin alpha cos beta)/(cos alpha+sin beta))

Show taht 2tan ^ (- 1) (tan ((alpha) / (2)) tan ((pi) / (4) - (beta) / (2))) = tan ^ (- 1) ((sin alpha cos beta) / (cos alpha + sin beta))

[ 7.If 0ltalphaltbetalt(pi)/(2) then [ 1) (tan beta)/(tan alpha)lt(alpha)/(beta), 2) (tan beta)/(tan alpha)gt(alpha)/(beta) 3) (tan alpha)/(tan beta)lt(alpha)/(beta) , 4) none ]]

If tan(alpha-beta)=(sin2 beta)/(3-cos2 beta), then ( i )tan(alpha)=2tan(beta)( ii) (1)/(2)tan(alpha)=tan(beta)( (ii) 2tan(alpha)=3tan(beta)( iv) 3tan(alpha)=2tan(beta)

If cos theta=(cos alpha cos beta)/(1-sin alpha sin beta), prove that one value of (tan)(theta)/(2)=((tan alpha)/(2)-(tan beta)/(2))/(1-tan(alpha)/(2)(tan beta)/(2))

Show that cos^(-1)((cos alpha+cos beta)/(1+cos alpha cos beta))=2tan^(-1)(tan((alpha)/(2))tan((beta)/(2)))

If cos alpha=(2cos beta-1)/(2-cos beta),0