Tan^-1[(acosx-bsinx)/(bcosx+asinx)]?

1 Answer
Sep 10, 2017

tan^-1[(acosx-bsinx)/(bcosx+asinx)]

=tan^-1[((acosx)/(bcosx)-(bsinx)/(bcosx))/((bcosx)/(bcosx)+(asinx)/(bcosx))]

=tan^-1[(a/b-tanx)/(1+a/bxxtanx)]

=tan^-1[(tanalpha-tanx)/(1+tanalphaxxtanx)],

where color(red)(a/b=tanalpha)

=tan^-1[tan(alpha-x)]

=alpha-x=tan^-1(a/b)-x