Mathematics I20745 marksNumerical: curve sketchingCurve sketching
Sketch the curve y = x3 + x.
Sketch the curve $y = x^3 + x$. [5]
As a polynomial, the domain is all real numbers $(-\infty, \infty)$. Since it is strictly increasing (shown below) and unbounded, the range is also $(-\infty, \infty)$. x-intercept (set $y=0$): $$x^3 + x = 0 \implies x(x^2+1) = 0$$ Since $x^2 + 1 0$, the only real solution is $x = 0$. y-intercept...