sin(x)^(4)+cos(x)^(4)=sin(x)*cos(x)

$$sin^{4}{left (x right )} + cos^{4}{left (x right )} = sin{left (x right )} cos{left (x right )}$$

-3*pi
x1 = —–
4

$$x_{1} = – frac{3 pi}{4}$$

pi
x2 = —
4

$$x_{2} = frac{pi}{4}$$

/ / _____________ / / _____________
| | ___ ___ / ___ || | | ___ ___ / ___ ||
| | 1 I*/ 3 / 2 */ 1 – I*/ 3 || | | 1 I*/ 3 / 2 */ 1 – I*/ 3 ||
x3 = – 2*re|atan|- – + ——- + ———————-|| – 2*I*im|atan|- – + ——- + ———————-||
2 2 2 // 2 2 2 //

$$x_{3} = – 2 Re{left({atan}{left (- frac{1}{2} + frac{sqrt{2}}{2} sqrt{1 – sqrt{3} i} + frac{sqrt{3} i}{2} right )}right)} – 2 i Im{left({atan}{left (- frac{1}{2} + frac{sqrt{2}}{2} sqrt{1 – sqrt{3} i} + frac{sqrt{3} i}{2} right )}right)}$$

/ / _____________ / / _____________
| | ___ ___ / ___ || | | ___ ___ / ___ ||
| |1 I*/ 3 / 2 */ 1 + I*/ 3 || | |1 I*/ 3 / 2 */ 1 + I*/ 3 ||
x4 = 2*re|atan|- + ——- – ———————-|| + 2*I*im|atan|- + ——- – ———————-||
2 2 2 // 2 2 2 //

$$x_{4} = 2 Re{left({atan}{left (frac{1}{2} – frac{sqrt{2}}{2} sqrt{1 + sqrt{3} i} + frac{sqrt{3} i}{2} right )}right)} + 2 i Im{left({atan}{left (frac{1}{2} – frac{sqrt{2}}{2} sqrt{1 + sqrt{3} i} + frac{sqrt{3} i}{2} right )}right)}$$

/ / _____________ / / _____________
| | ___ ___ / ___ || | | ___ ___ / ___ ||
| |1 I*/ 3 / 2 */ 1 + I*/ 3 || | |1 I*/ 3 / 2 */ 1 + I*/ 3 ||
x5 = 2*re|atan|- + ——- + ———————-|| + 2*I*im|atan|- + ——- + ———————-||
2 2 2 // 2 2 2 //

$$x_{5} = 2 Re{left({atan}{left (frac{1}{2} + frac{sqrt{2}}{2} sqrt{1 + sqrt{3} i} + frac{sqrt{3} i}{2} right )}right)} + 2 i Im{left({atan}{left (frac{1}{2} + frac{sqrt{2}}{2} sqrt{1 + sqrt{3} i} + frac{sqrt{3} i}{2} right )}right)}$$

/ / _____________ / / _____________
| | ___ / ___ ___|| | | ___ / ___ ___||
| |1 / 2 */ 1 – I*/ 3 I*/ 3 || | |1 / 2 */ 1 – I*/ 3 I*/ 3 ||
x6 = 2*re|atan|- + ———————- – ——-|| + 2*I*im|atan|- + ———————- – ——-||
2 2 2 // 2 2 2 //

$$x_{6} = 2 Re{left({atan}{left (frac{1}{2} – frac{sqrt{3} i}{2} + frac{sqrt{2}}{2} sqrt{1 – sqrt{3} i} right )}right)} + 2 i Im{left({atan}{left (frac{1}{2} – frac{sqrt{3} i}{2} + frac{sqrt{2}}{2} sqrt{1 – sqrt{3} i} right )}right)}$$

x1 = 0.785398078436000

x2 = -21.2057504869000

x3 = -77.7544181730000

x4 = -68.3296396747000

x5 = -21.2057499034000

x6 = -96.6039741356000

x7 = 2344.41351770000

x8 = -43.1968990510000

x9 = 79.3252141517000

x10 = 25.9181394593000

x11 = 85.6083999577000

x12 = -84.0376034469000

x13 = -36.9137136765000

x14 = -87.1791961742000

x15 = 38.4845098900000

x16 = 32.2013244271000

x17 = 63.6172513831000

x18 = 19.6349542334000

x19 = -124.878308021000

x20 = 22.7765466450000

x21 = -74.6128255877000

x22 = -27.4889358431000

x23 = -5.49778726557000

x24 = -99.7455667547000

x25 = -33.7721210086000

x26 = -2.35619434172000

x27 = 32.2013247418000

x28 = -62.0464548649000

x29 = 44.7676952126000

x30 = 41.6261028084000

x31 = -18.0641577021000

x32 = -46.3384914926000

x33 = 13.3517685635000

x34 = 3.92699087875000

x35 = -68.3296400683000

x36 = 88.7499923505000

x37 = 98.1747705002000

x38 = -159.435827340000

x39 = 76.1836219128000

x40 = 57.3340656190000

x41 = -30.6305285035000

x42 = -40.0553062833000

x43 = 161.006623343000

x44 = -90.3207886442000

x45 = -71.4712329979000

x46 = 69.9004366197000

x47 = 47.9092880396000

x48 = 66.7588437811000

x49 = -11.7809724257000

x50 = 82.4668070460000

x51 = -55.7632695910000

x52 = -24.3473429171000

x53 = 91.8915851995000

x54 = 60.4756584679000

x55 = -93.4623815751000

x56 = 54.1924733268000

x57 = -8.63937996786000

x58 = 10.2101761577000

x59 = -11.7809724859000

x60 = -49.4800844206000

x61 = -65.1880476135000

x62 = -52.6216770435000

x63 = 35.3429170916000

x64 = 16.4933613121000