We have to prove that `4(cos^3 10 + sin^3 10) = 3(cos 10 + 2*sin 20)`

cos 10 = 0.9848

sin 10 = 0.1736

sin 20 = 0.3420

`4(cos^3 10 + sin^3 10) = 4((0.9848)^3 + (0.1736)^3) = 4(0.9602) = 3.8412`

`3(cos 10 + 2*sin 20) = 3(0.9848 + 2*0.3420) `

`= 3(0.9848 + 0.6840) = 3*1.6688 = 5.0064`

As 3.8412 is not equal to 5.0064, the two sides are not equal.

**It is not possible to prove the given expression.**