00:01
Okay, we start off with u of x comma t, which is equal to the summation of n equal and infinity of a and sign.
00:18
N x cosine 3 and t plus summation of n equal one to infinity of b and sign.
00:39
X, sign, 3, and t u of x, comma, 0 is equal to summation, and an equal 1, u.
00:55
A, and sign, and x, which is equal to sign 4x, 4, x, plus 7, sine, sine, 5, x, the coefficient is 8, 4 ,000, 4, 6, 6, the coefficientity is 8, 4, 4, 6, 6, 6, 6, 6, the is equal to 1 ,8, 85, equal to 7.
01:23
And everything else is zero.
01:25
So u of x, comma, t is equal to sine of 4 x, cosine, plus 7 ,000, plus 7, 5, x, cosine, plus 7, 5, x, cosine, plus, summation of n equal 1 tini and sign and x 3 and t partial u x partial t is equal to 12 minus 12 sign or x sign 12 t plus minus 105 5x sign 15 t plus a point in 3 bn3 n x sign and x x comes 0 partial t is equal to equal to summation of any normal one dain, b and three n.
03:34
Sign and x, which is equal to x, pi minus x...