Basically, in my opinion it is a continuous function since at its peak (maxima) left hand limit=right hand limit=functional value although the function/wave consists of two straight line equations one of +ve gradient and one of -ve gradient.
Therefore, the triangle wave has no discontinuous jumps, but the slope changes discontinuously twice per cycle (This is due to the fact that the triangular waveform is formed by two different functions i.e. two different straight lines as their gradients are different ).
Therefore kindly suggest your opinion whether Triangular wave is continuous or discontinuous function/waveform with suitable documents.
There is a difference between a continuous function and a differentiable function. A triangular wave is continuous but not differentiable. A square wave is discontinuous (and possibly double valued!-and if so by definition not a function) as well as not differentiable.