The teacher will be very surprised to see your correct solution 😉
/x pi\ cos|- + --| = 0 \2 4 /
with the change of sign in 0
sum
pi 5*pi -- + ---- 2 2
=
3*pi
product
pi 5*pi --*---- 2 2
=
2 5*pi ----- 4
5*pi^2/4
pi x1 = -- 2
5*pi x2 = ---- 2
x2 = 5*pi/2
x1 = -29.845130209103
x2 = -67.5442420521806
x3 = 64.4026493985908
x4 = -36.1283155162826
x5 = -92.6769832808989
x6 = -61.261056745001
x7 = -98.9601685880785
x8 = 32.9867228626928
x9 = -4.71238898038469
x10 = -10.9955742875643
x11 = 26.7035375555132
x12 = -105.243353895258
x13 = 95.8185759344887
x14 = -17.2787595947439
x15 = -86.3937979737193
x16 = -48.6946861306418
x17 = 76.9690200129499
x18 = 45.553093477052
x19 = -2913.82718620453
x20 = -80.1106126665397
x21 = 7.85398163397448
x22 = 102.101761241668
x23 = 14.1371669411541
x24 = -563.915881319368
x25 = 70.6858347057703
x26 = 83.2522053201295
x27 = 51.8362787842316
x28 = 20.4203522483337
x29 = 1.5707963267949
x30 = 89.5353906273091
x31 = 58.1194640914112
x32 = -218.340689424491
x33 = -54.9778714378214
x34 = -42.4115008234622
x35 = -256.039801267568
x36 = 39.2699081698724
x37 = -23.5619449019235
x38 = -73.8274273593601
x38 = -73.8274273593601