It can be helpful to classify a differential equation, so that we can predict the techniques that might help us to find a function which solves the equation. Two classifications are the order of the equation -- (what is the highest number of derivatives involved) and whether or not the equation is linear .Linearity is important because the structure of the the family of solutions to a linear equation is fairly simple. Linear equations can usually be solved completely and explicitly. Determine whether or not each equation is linear:1. (1+y2)(d2y/dt2)+t(dy/dt)+y=et2. t2(d2y/dt2)+t(dy/dt)+2y=sin t3. (d3y/dt3)+t(dy/dt)+(cos2(t))y=t34. y''-y+y2=0You have 10 choices to choose for each problem:a. 1st. order linear differential equationb. 2nd. order linear differential equationc. 3rd. order linear differential equationd. 4th. order linear differential equatione. 5th. order linear differential equationf. 1st. order non-linear differential equationg. 2nd. order non-linear differential equationh. 3rd. order non-linear differential equationi. 4th. order non-linear differential equationf. 5th. order non-linear differential equation

Answer:The equations are not given but the clue to your answer is given below:Step-by-step explanation:So the question above talks generally about differential equations (equations whose derivatives can be found) and then describes them thus - the order of a differential equation and the linearity status of a differential equation.To determine whether or not each of the absent equations is linear, check for the following characteristics of linearity:1. The maximum number or power that any variable in a linear equation is raised to is 1.Example: 2x² + 6y = 43y is NOT a linear equation because some or all (in this case, variable x) of the variables in it are raised to a power greater than 1. Variable x is raised to the power of 2.2. An equation (a linear equation, in this case) contains an 'equal to' sign. This is the reason why it's called an equation. There is a mathematical expression on each side of the equal to sign. Take note of this, just incase one of the options in your question has no equal to sign.Example: 2x + 6y is NOT a linear equation. It is a linear expression. It contains no equal to sign that compares two distinct mathematical expressions.3. A linear equation usually has not more than two variables. It is not complex or difficult to solve.Example: 2x + 6y = 43z is NOT a linear equation.