(1+tanθ)/(sinθ+cosθ)=secθ
what to do?
\[\frac{1+\tan \theta}{\sin \theta+\cos \theta}=\sec \theta\]
verify indentity
(1+tanθ)/(sinθ+cosθ) = 1/cosθ cosθ/(sinθ +cosθ) = 1/(1+tanθ) tanθ = sinθ/cosθ 1 + tanθ = 1 + sinθ/cosθ = (cosθ + sinθ)/cosθ 1/(1+tanθ) = cosθ/(cosθ + sinθ) which is what is in the left side :)
put any value of theta and you will se that the rhs and lhs are same
RHS\[\sec \theta=\frac{\sin \theta + \cos \theta}{\sin \theta +\cos \theta}\sec \theta\]\[=\frac{1+\tan \theta}{\sin \theta + \cos \theta}=RHS\]
you could actually do it without my first steps .. : 1 + tanθ = 1 + sinθ/cosθ = (cosθ + sinθ)/cosθ so put it in the original : ( (cosθ + sinθ)/cosθ) / ( sinθ + cosθ) =1 /cosθ ( (cosθ + sinθ)/(cosθ( sinθ + cosθ))) = 1/cosθ then 1/cosθ = 1/cosθ whatever you prefer
i think that u got it..
keep right side, solve left side?
?
you can do that also
\[\frac{1+\tan \theta}{\sin \theta+\cos \theta }=\frac{\cos \theta (1 +\tan \theta)}{\cos \theta (\sin \theta +\cos \theta)}\]\[\frac{\sin \theta + \cos \theta}{\cos \theta(\sin \theta +\cos \theta)}=1/\cos \theta =\sec \theta =RHS\]
I don't get
\[\frac{\cos \theta+\sin \theta}{\frac{\cos \theta}{\sin \theta+\cos \theta}}\]I get from here
\[=\frac{(\cos \theta+\sin \theta)^2}{\cos \theta}\]
what are you doing????
start from any one of the sides..either RHS or LHS
I do 1+tan
take 1+tan/(sin + cos)
multiply num and den with cos and see my previous post
now got it?
Join our real-time social learning platform and learn together with your friends!