Legendre polynomials form a basis set for the function space in the interval [-1,1] with the orthogonality realiton;
P_m(x)P_n(x) dx= 2/(2n+1)
n,m
P_0(x))=1, P_1(x)=x, P_2(x)=(3x^2)-1, P_3(x)=((5x^3)-3x)/2, P_4(x)=(35x^4-30x^2 +3)/8
Find c_1 with expasion coeffcient
f(X)=5x^4+8x^2+9x= sum[n,4] c_n*p_n(x)

Legendre polynomials form a basis set for the function space in the interval [−1,1] with the orthogonality relation ∫−11Pm(x)Pn(x)dx=2n+12δn,m Using the above relation and the polynomials given below P0(x)=1,P1(x)=x,P2(x)=(3x2−1)/2,P3(x)=(5x3−3x)/2,P4(x)=(35x4−30x2+3)/8 find the expansion coeffients c1 for the function given below. f(x)=5x4+8x2+9x=∑n=04cnPn(x)