sorry. the paper says -1 less than or equal to x greater than or equal to 1 but I think it should be -1 less than or equal to x less than or equal to 1... as in [-1,1]
[b]1. Make these three equations orthonormal to each other in the interval 1 less than or equal to x greater than or equal to 1 (this may be a typo as I think it should read 1 less than or equal to x less than or equal to one) by determining the appropriate values for the coefficients a b c d e...