Kinematics

I need verification abt the following(whether it is correct or not) {as i saw θ'+ θ = л/2-β many times in solutions for some questions.}
In case of inclined plane
when Range is same for given speed of projection
For R to be same for two values of θ(Letθ' and θ )
sin(2θ'-β) = sin(2θ-β)

2θ'-β = л- (2θ-β)
Then accordingly it should be θ'+ θ = л/2+ β
So it was printing mistake all the time or i m mistaking in deriving it,is this not the correct way to derive?
Please consider my query.
and reply soon as i m getting mad over this and my other topics are waiting for me.

can you please define what is

Code:

\theta

and other symbols

i forgot the formulas,so will need to know what are they

sorry.i thought,its not needed.

two particles are projected up with a speed u at an angle θ’ and θ respectively with the horizontal onto an inclined plane of inclination β.
Condition over here is : Range is same for both projection.

Anyone..............
please clear my doubt.

Please tell me the wat u get after deriving eq for Range(when object projected from upside on incline plane.)
and then check for max range.and then come to the conclusion.do u find anything strange in that.

my this doubt is solved.Thank u.