Determine which of the following equations are exact, and solve the ones that are. 1. ( x + = )dy + y dx =0 2. ( 2xy3 + yCos x ) dx + ( 3x2y? + Sin x ) dy = 0 3. Cos x Cosy dx + 2 Sin x Sin y Cos y dy = 0 4. (1 +x ) dy + (2 + y ) dx =0 5. ( x3 + y ) dx + ( x - y3 ) dy=0 6. ( Sin x Sin y - xev ) dy = ( ex + Cos x Cos y ) dx 7. ( 2y2 - 4x + 5 ) dx = ( 4 - 2y + 4xy ) dy 8. (Sin x tan y + 1 ) dx + Cos x Sec? y dy = 0 9. # Sin + dy - _ Sin - dx = 0 10. dx = _2/ dx + 1_x, dy "It is not the STRONGEST, the BRIGHTEST, the FASTEST, et., who normally gets it. It is the most DILIGENT worker who gets it..."