Afunction f (t )defined on an interval 0less thantless thanl is given. find the fourier cosine and sine series of f and sketch the graphs of the two extensions of f to which these two series converge. f (t )equalsleft brace start 2 by 2 matrix 1st row 1st column 5 t comma 2nd column 0 less than t less than over equal 5 ; 2nd row 1st column 50 minus 5 t comma 2nd column 5 less than over equal t less than 10 endmatrix type the first four non-zero terms of the fourier cosine series of f.