Given secalpha=secbetasecgamma+tanbetatangamma How will you show? secbeta =secgammasecalpha+-tangammatanalpha

1 Answer
Jul 2, 2016

As below

Explanation:

Given relation

secalpha=secbetasecgamma+tanbetatangamma

=>secalpha-secbetasecgamma=tanbetatangamma

color(green)("Squaring both sides")

=>(secalpha-secbetasecgamma)^2=tan^2betatan^2gamma

=>sec^2alpha+sec^2betasec^2gamma-2secalphasecbetasecgamma=tan^2betatan^2gamma

=>-2secalphasecbetasecgamma=-sec^2alpha+tan^2betatan^2gamma-sec^2betasec^2gamma

=>-2secalphasecbetasecgamma=-sec^2alpha+(sec^2beta-1)(sec^2gamma-1) -sec^2betasec^2gamma

=>-2secalphasecbetasecgamma=-sec^2alpha+cancel(sec^2betasec^2gamma)+1-sec^2gamma-sec^2beta-cancel(sec^2betasec^2gamma)

=>sec^2beta-2secalphasecbetasecgamma=-sec^2alpha+1-sec^2gamma

color(blue)("Adding "(sec^2gammasec^2alpha)" both sides "

=>sec^2beta-2secalphasecbetasecgamma+sec^2gammasec^2alpha=sec^2gammasec^2alpha-sec^2alpha+1-sec^2gamma

=>(secbeta-secgammasecalpha)^2=sec^2alpha(sec^2gamma-1)-1(sec^2gamma-1)

=>(secbeta-secgammasecalpha)^2=(sec^2gamma-1)(sec^2alpha-1)

=>(secbeta-secgammasecalpha)^2=tan^2gammatan^2alpha

=>(secbeta-secgammasecalpha)=+-sqrt(tan^2gammatan^2alpha)

=>secbeta-secgammasecalpha=+-tangammatanalpha

=>color(BLUE)(secbeta=secgammasecalpha+-tangammatanalpha)

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