Question

sin^3(x)+2cos^5(x)=sqrt10

Answer 1

1/8 (6 sin(x)-2 sin(3 x)+10 cos(x)+5 cos(3 x)+cos(5 x)) = sqrt(10)

TrigReduce[2 Cos[x]^5 + Sin[x]^3 == Sqrt[10]]

(10 Cos[x] + 5 Cos[3 x] + Cos[5 x] + 6 Sin[x] - 2 Sin[3 x])/8 == Sqrt[10]