..im really stuck on this. can someone please explain?

Question

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Figure A [[which i tried to recreate below]] is a partial graph of the position function x(t) for a simple harmonic oscillator with an angular frequency of 1.1 rad/s.

[a].....x(cm).......
........5-|-........
.........-|-........
=======.3-|-........
.......========.....
........1-|-...=====
----------|---------t
.......-1-|-........
.........-|-........
.......-3-|-........
.........-|-........
.......-5-|-........

Figure B is a partial graph of the corresponding velocity function v(t).

[b]....v(cm/s)......
........5-|-........
.........-|-........
........3-|-........
.........-|-........
........1-|-........
----------|---------t
.......-1-|-........
.........-|-........
=======-3-|-........
.......========.....
.......-5-|-...=====

What is the phase constant of the SHM if the position function x(t) is given the form x = xmcos(ωt + φ)?

φ = ____ rad/s

..... the example in the book had an angular frequency of 1.2 rad/s. & the answer it gave was 1.03 rad/s.

sorry that the 'graphs' look distorted on this page that your viewing... i recommend copying the graph and pasting it in the ANSWER box below on this page and it should look right :)