[VA] Short & Sweet Math Challenge #24: "2019 Spring Special 5-tier"

[Juan14]

For the last challenge.
Let cin(x) = sin(x+A), we have:
sin(sin(sin(x+A)+A)+A) = sin(x) or
sin(sin(x+A)+A)+A = x
For a given value of x, we can solve the last equation for A (A is a function of x).

Here is the program for the hp 50g:

«
→ x
«
'SIN(SIN(x+A)+A)+A-x'
'A' 1 ROOT x + SIN →NUM
»
»

x_____cin(x)
0_____0.
0.2___0.19954743606
0.4___0.39617257453
0.6___0.586447829132
0.8___0.761 006258889
1_____0.906981195071
π/2____.835085096711
-0.71__-0.684625012855
2.019__4.81961624069E-3

There are so many ways to define the function cin(x) in a similar way, that's why I didn't post my solution before, but here it is anyway :-)