1. Find a function whose square plus the square of its derivative is 1. (5 pts) dy 2. Can any solution of dr v(4) = -3 cross the r-axis? Do you think that + = 1 is an dy implicit solution of the IVP 0? (10 pts) da 3. Construct a lincar first-order differential equation for which all nonconstant solutions approach the horizontal asymptote as y 4 as a- 0. (5 pts) %3! 4. In determining integrating factors of linear DEs, the constant of integration in the evaluation of SP(?) dr. Explain why using SP(2) da + c has no effect on the solution. (10 pts)