Use a Calculator to Find an Approximate Value of Each $\cos ^ { - 1 } ( - 0.25 )$

question 45

Essay

Use a calculator to find an approximate value of each expression correct to five decimal places, if it is defined.
(a)
$\cos ^ { - 1 } ( - 0.25 )$
(b)
$\sin ^ { - 1 } ( 3 / 4 )$

---

Definitions:

Direct Materials Purchases Variance

The difference between the actual cost of direct materials purchased and the expected (or standard) cost, used for budgeting and cost control purposes.

Standard Costs

Predetermined or budgeted costs for materials, labor, and overhead used for cost control and financial planning.

Materials Quantity Variance

The variance between the real amount of materials consumed in the manufacturing process and the anticipated standard amount.

Direct Materials Purchases Variance

The difference between the actual cost of direct materials purchased and the expected, or budgeted, cost.