Find the number of solutions of the equation `sinx=x^2+x+1.`

Explanation

Let `f(x)=sin x` and
`g(x)=x^(2)+x+1=(x+(1)/(2))^(2)+(3)/(4)`
As down in the figure, graphs of `y=f(x) and y=g(x)` do not intersect at any point. Therefore, there is no solution.