Taking you through the sketch graphs.
A normal sine function is a bump beteen 0 and pi [180degrees if you like], then a dip under the axis between pi and 2xpi.
The absolute value of the sine function is just two bumps beside each other.
Please acknowlege you understand that.
I knew that.
And i know the graph of |cos x| too but i don't know to add |sin x|+|cos x|.