How can I solve a complex equation without a good calculator?

[Zashmar]

15=343*sin*x(0.357143 (+1.41421 sqrt(2389.-2401. cos(2. x))+98. sin(x))-4.9((0.357143 (+1.41421 sqrt(2389.-2401. cos(2. x))+98. sin(x)))^2


I do not have a good enough calculator


please help solve for x.

Thank you

 

[BvU]

Funny, you have the whole internet, but you claim not to have a good enough calculator.
Suppose I want to help, what can I do ?