 मज्योल 77, पर्फेक चव्स्टौट्र्च्य आँइ प्र्फ्ट्ट क्म्लिमेंट जब हम प्रुड्क्यों की बात करते है, तो हम ने भाई बात की के प्रुड्क्यों उट्ट्टियार लिक चेद तॢ्टिर्न का आएने when you talk about inputs, it might be possible two inputs are perfect substitutes. which substitutes can be perfect substitutes, if I talk about livestock production, then suppose there are two types of the fodder, we talked about dry fodder, we talked about green fodder. I can say that it might be possible that for livestock these two inputs are perfect substitutes. say that you can use a good fodder or any other fodder, it can serve as a fodder for the animal. I can also say that we talked about agricultural output, that there is wheat production, to produce wheat it requires certain quantity of input. we categorized it in the form of labour and capital. what was there in the wheat, there were some weeds there, what was the need to remove those weeds? say that you hire labourers and remove the weeds. second is that if you spray any herbicide there, in the case of wheat, it might be difficult to understand this example. we talk about cotton. for the cotton production, you need certain quantity of labour and capital. again there are certain weeds in the field. how can you remove them? say that you hire labourers or spray any herbicide. and my assumption here is that these two inputs are perfect substitutes of each other. and when we will discuss this with reference to Isoquant, Isoquant is a curve that reports same level of output against different combination of two inputs. and if my assumption is that two inputs are perfect substitutes of each other, then our Isoquant is our downward sloping straight line. as I am reporting in this diagram. and in this case slope of Isoquant is constant. the point where I will measure slope of Isoquant, slope is same. and the marginal rate of technical substitution is constant. under imperfect substitute situation, what was the situation that the marginal rate of technical substitution declines as we move down along an Isoquant. but what is here is that we are moving along an Isoquant, but there is no change in the marginal rate of technical substitution. now something like this can happen that two inputs are perfect complement. what can be an example? to make production to produce agricultural output, it requires a certain combination of labour and capital. what can be the form of capital? there is a tractor that is used to carry out some activities in the field. what I need to run the tractor? I need one labour. if I talk about this tractor and the labour perspective, what will happen here? an exact combination of labour and capital is required to run tractors. let me talk about two capital goods. if I have a cultivator, what will be the requirement of that cultivator? I need one tractor. cultivator without tractor will not serve any purpose to the farmer. when we need a particular combination of input to produce agricultural output, then we will say that two inputs are perfect complement. and when we say that two inputs are perfect complement, then an Isoquant is a right angled curve. in this case, Isoquant will be a 90 degree angle curve. in this case, slope of Isoquant will be either 0 or infinite. in this case, the perpendicular part of the vertical part of Isoquant will be infinite. and the horizontal part of Isoquant will be 0. and when you talk about the marginal rate of technical substitution, in this case, what can happen? that will also be either 0 or infinite. now if I summarize all these things, what does this indicate to me? that it might be possible that an Isoquant is a downward sloping straight line. in this case, when two inputs are perfect substitute. Isoquant may have a right angled curve when two inputs are perfect complement of each other. but mostly when we describe Isoquant, then our assumption is that two inputs are neither perfect complement nor perfect substitutes. and what will be the shape of Isoquant? this is a curve that is convex towards origin.