If ar2 + br + c = 0 has equal roots r1, show that L[ert] = a(ert)" + b(crt)' + cert = a(r - r1 )2er1. Since the right side of is zero when r = r1, it follows that exp(r1,t) is a solution of L[y] = ay" + by' + cy = 0. Differentiate with respect to r and interchange differentiation with respect to r and with respect to t, thus showing that Since the right side of is zero when r = r1 conclude that t exp(r1 t) is also a solution of L[V] =0. Determine a suitable form of Y(t) if the method of undetermined coefficients is to be used. y" + 2y' + 5y = 3et-t cos2t - 2te-2t cost

Solution is in the following attachment.

Step-by-step explanation:

walter needs to make at least 5 more cookies but no more than 40. 5 ≥ x ≥ 40;

step-by-step explanation:

walter has to make a minimum of 20 cookies. he already has 15 cookies made, so he must make 5 more to meet the minimum.

the maximum amount of cookies he can make is 55. he already has 15, so he has to make no more than 40 more cookies to meet the maximum.

so firstly, we need to isolate the y variables to be able to solve these inequalities. firstly, add 0.5x on both sides of the first inequality and subtract 1.5x on both sides of the second inequality:

now since the slope is positive for the first inequality, this means that the line going upwards belongs to the first inequality, and the line going downwards belongs to the second inequality.

next, since y ≥ in the first inequality, this means that the shaded region will be above the first inequality's line, thus shading regions a and b.

next, since y ≤ in the second inequality, this means that the shaded region is going to be below this line, thus shading regions a and c.

since both lines shade region a, this means that region a is the solution.

step-by-step explanation:

mark brainliest!