3.6.5 Convert to Integral
An equation is converted to an integral equation by using the subject
as the integrator and the expressions on either side as the
integrands of two integral expressions.
Since there is only one subject, both integrals will have the same integrator.
For example,
sin x=sin .{x} is transformed to
∫sin x ⅆx=∫sin x ⅆx.