Consider the equation 2cos^2x + sinx - 1 = 0
a) Explain why the equation cannot be factored.
b) Suggest a trigonometric identity that can be used to remove the problem identified in part a).
c) Apply the identity and rearrange the equation into a factorable form.
d) Factor the equation.
e) Determine all solutions in the interval x E [0,2pi].