00:01
Okay, so here from m squared plus 4 is equal to 0, we get that m is going to be equal to positive or negative 2 times i.
00:09
So the complementary function, then y subc is equal to c1 cosine of 2x plus c2 times sine of 2x.
00:16
Now, when we have that 0 is less than equal to x, which is less than equal to pi over 2, we let y sub p be equal to a times co.
00:30
Of x plus b times sine of x so then the first derivative here is negative the quantity a cosine of x plus b sine of x and um y double prime plus 4 y is equal to sign of x so this then gives us that three times a cosine of x plus b times sine of x um is equal to sign of x and then equating the coefficients of the like terms gives us that 3a is equal to 0, gives us a is equal to 0, and then 3b is equal to 1, giving us that b is equal to 1 3rd.
01:17
So we get then that y sub p here is equal to 1 3rd times sine, oops, times sign of x.
01:27
And therefore we have that y is equal to c1, cosine of 2x plus c2, sine of 2x, plus 1.
01:34
Third sign of x on the interval from 0 to pi over 2.
01:38
Now, when x is greater than pi over 2, we let y sub p be equal to a, then we get y to a prime plus 4 y equals 0 implies 4a is equal to 0...