The teacher will be very surprised to see your correct solution 😉
/x pi\ sin|- - --| = 0 \4 8 /
with the change of sign in 0
Divide both parts of the equation by -1
pi x1 = -- 2
9*pi x2 = ---- 2
x2 = 9*pi/2
sum
pi 9*pi -- + ---- 2 2
=
5*pi
product
pi 9*pi --*---- 2 2
=
2 9*pi ----- 4
9*pi^2/4
x1 = 39.2699081698724
x2 = 103586.163770489
x3 = -86.3937979737193
x4 = -98.9601685880785
x5 = -174.358392274234
x6 = 14.1371669411541
x7 = -48.6946861306418
x8 = 139.800873084746
x9 = -589.048622548086
x10 = 1.5707963267949
x11 = -450.818545790135
x12 = 51.8362787842316
x13 = -10.9955742875643
x14 = 26.7035375555132
x15 = -23.5619449019235
x16 = 190.066355542182
x17 = 102.101761241668
x18 = 76.9690200129499
x19 = -36.1283155162826
x20 = -73.8274273593601
x21 = 64.4026493985908
x22 = 89.5353906273091
x23 = -61.261056745001
x23 = -61.261056745001