(eks-ten'sÅr, -sÅr), [TA] 1  A muscle the contraction of which causes movement at a joint with the consequence that the limb or body assumes a more straight line, or so that the distance between the parts proximal and distal to the joint is increased or extended; the antagonist of a flexor. See: muscle.
All other things being equal, using internal rate of return (IRR) and net present value (NPV) measurements to evaluate projects often results in the same findings. However, there are a number of projects for which using IRR is not as effective as using NPV to discount cash flows.
Each cash flow, specified as a value, occurs at a scheduled payment date. IRR(values, [guess]) Determine the internal rate of return using cash flows that occur at regular intervals, such as monthly or annually. Each cash flow, specified as a value, occurs at the end of a period. If there is an additional cash flow at the start of the first period, it should be added to the value returned by the NPV function. See Example 2 in the NPV Help topic.