(1). The order of the equation (y') + (y') sinx + (cosx] )y" =0 is A. 1 B. 2 C. 3 D. 5 (2). This equation Y = 4x2 - yis ( dx A. variable separable differential equation B. linear equation C. exact differential equation D. Bernoulli equation (3). The constant solutionof the equation x(y' -1)dx + y(x2 -1)dy =0 is A. y = +1,x =+1 B. y = +1 C. x=$1 D. y= 1,x =1 (4). Supposing the linearly independent function y,,)2,y, are all solutions to the eqaution y + p(x)y' + q(x)y=f(x) , C ,C, are all arbitrary constant, then the general solution to this equation is ( A. Cy, + C272 + V's B. Cy, + Czy2 -(C +C2)y's C. C,y, + Czy2 - (1-C, -C2)y; D. Cy, + Czy2 + (1-C, -C2)y's (5). All the solutions of a linear homogeneous equation of order n consist a ) linear space. 4. " dimensional B. n+1 dimensional C. n-1 dimensional D. n +2 dimensional