What is the order of the following difference equation? Explain your answer\({y_{k + 3}} + {a_1}{y_{k + 2}} + {a_2}{y_{k + 1}} + {a_3}{y_k} = 0\).

Short Answer

Expert verified

If \({a_3} = 0\) and \({a_2} \ne 0\), the order is 2.

If \({a_3} \ne 0\), the order is 3.

If \({a_3} = {a_2} = 0\) and \({a_1} \ne 0\), the order is 1.

If \({a_3} = {a_2} = {a_1} = 0\), the order is 0.

Step by step solution

01

Discuss the attributes of a difference equation

The given difference equation is \({y_{k + 3}} + {a_1}{y_{k + 2}} + {a_2}{y_{k + 1}} + {a_3}{y_k} = 0\). The order of a difference equation depends on the values of the coefficients \({a_1}\), \({a_2}\), and \({a_3}\).

02

Discuss the cases corresponding to the values of the coefficients

If \({a_3} = 0\) and \({a_2} \ne 0\), then the difference equation can be reduced to \({y_{k + 2}} + {a_1}{y_{k + !}} + {a_2}{y_k} = 0\), which implies that its order is 2.

If \({a_3} \ne 0\), then the difference equation cannot be reduced further, which implies that its order is 3.

If \({a_3} = {a_2} = 0\) and \({a_1} \ne 0\), then the difference equation can be reduced to \({y_{k + 1}} + {a_1}{y_k} = 0\), which implies that its order is 1.

If all the coefficients are zero, that is, \({a_3} = {a_2} = {a_1} = 0\), then the difference equation does not possess any signal value, which implies that its order is 0.

03

Draw a conclusion

If \({a_3} = 0\) and \({a_2} \ne 0\), the order is 2.

If \({a_3} \ne 0\), the order is 3.

If \({a_3} = {a_2} = 0\) and \({a_1} \ne 0\), the order is 1.

If \({a_3} = {a_2} = {a_1} = 0\), the order is 0.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with Vaia!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

Question 18: Suppose A is a \(4 \times 4\) matrix and B is a \(4 \times 2\) matrix, and let \({{\mathop{\rm u}\nolimits} _0},...,{{\mathop{\rm u}\nolimits} _3}\) represent a sequence of input vectors in \({\mathbb{R}^2}\).

  1. Set \({{\mathop{\rm x}\nolimits} _0} = 0\), compute \({{\mathop{\rm x}\nolimits} _1},...,{{\mathop{\rm x}\nolimits} _4}\) from equation (1), and write a formula for \({{\mathop{\rm x}\nolimits} _4}\) involving the controllability matrix \(M\) appearing in equation (2). (Note: The matrix \(M\) is constructed as a partitioned matrix. Its overall size here is \(4 \times 8\).)
  2. Suppose \(\left( {A,B} \right)\) is controllable and v is any vector in \({\mathbb{R}^4}\). Explain why there exists a control sequence \({{\mathop{\rm u}\nolimits} _0},...,{{\mathop{\rm u}\nolimits} _3}\) in \({\mathbb{R}^2}\) such that \({{\mathop{\rm x}\nolimits} _4} = {\mathop{\rm v}\nolimits} \).

Find a basis for the set of vectors in\({\mathbb{R}^{\bf{2}}}\)on the line\(y = {\bf{5}}x\).

Define by \(T\left( {\mathop{\rm p}\nolimits} \right) = \left( {\begin{array}{*{20}{c}}{{\mathop{\rm p}\nolimits} \left( 0 \right)}\\{{\mathop{\rm p}\nolimits} \left( 1 \right)}\end{array}} \right)\). For instance, if \({\mathop{\rm p}\nolimits} \left( t \right) = 3 + 5t + 7{t^2}\), then \(T\left( {\mathop{\rm p}\nolimits} \right) = \left( {\begin{array}{*{20}{c}}3\\{15}\end{array}} \right)\).

  1. Show that \(T\) is a linear transformation. (Hint: For arbitrary polynomials p, q in \({{\mathop{\rm P}\nolimits} _2}\), compute \(T\left( {{\mathop{\rm p}\nolimits} + {\mathop{\rm q}\nolimits} } \right)\) and \(T\left( {c{\mathop{\rm p}\nolimits} } \right)\).)
  2. Find a polynomial p in \({{\mathop{\rm P}\nolimits} _2}\) that spans the kernel of \(T\), and describe the range of \(T\).

Question 11: Let \(S\) be a finite minimal spanning set of a vector space \(V\). That is, \(S\) has the property that if a vector is removed from \(S\), then the new set will no longer span \(V\). Prove that \(S\) must be a basis for \(V\).

In Exercise 5, find the coordinate vector \({\left( x \right)_{\rm B}}\) of x relative to the given basis \({\rm B} = \left\{ {{b_{\bf{1}}},...,{b_n}} \right\}\).

5. \({b_{\bf{1}}} = \left( {\begin{array}{*{20}{c}}{\bf{1}}\\{ - {\bf{3}}}\end{array}} \right),{b_{\bf{2}}} = \left( {\begin{array}{*{20}{c}}{\bf{2}}\\{ - {\bf{5}}}\end{array}} \right),x = \left( {\begin{array}{*{20}{c}}{ - {\bf{2}}}\\{\bf{1}}\end{array}} \right)\)

See all solutions

Recommended explanations on Math Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.

Sign-up for free