The value of sin−1x+cos−1x(|x|≥1) is
sin−1x+cos−1x
sin−1x=θ1⇒sinθ1=x
cos−1x=θ2⇒cosθ2=x
tanθ1=x√1−x2
tanθ2=√1−x2x
tan(θ1+θ2)=tanθ1+tanθ21−tanθ1tanθ2
=x√1−x2+√1−x2x1−1
=x2+1−x2x√1−x2(0)
tan(θ1+θ2)=∞
θ1+θ2=π2
∴sin−1x+cos−1x=π2
Inverse circular functions,Principal values of sin−1x,cos−1x,tan−1x. tan−1x+tan−1y=tan−1x+y1−xy, xy<1 π+tan−1x+y1−xy, xy>1. Evaluate the following : (a) sin[π3−sin−1(−12)] (b) sin[π2−sin−1(−√32)]