The cosine function used in trigonometry can be defined as an alternating series in calculus even though they are introduced in elementary algebra as the ratio of sides of a right triangle. The cosine can be rewritten as

Use PYTHON to write a function called approximate_cos() which consumes a float x and a tolerance and approximates cos(x) within the tolerance. The function should return how many iterations that were needed in order to approximate cos(x) within the specified tolerance.