21. Determine the Jacobian matrix for the following isoparametric elements. If the temperature at the nodes of both elements are {Ti, T2, T3, T4} = {100, 90, 80, 90}, compute the tempera¬

ture at the midpoint of the element and at the midpoint of the edge between connecting Nodes 1 and 4.

2 (1,12)'

3(1,1), 1 (2,12)

,4 (2,1)

2 (0,4)'

3 (0,0), ,4(18,0)