Which of these is a solution of xdy/dx + y = 0?

Differential Equations · Question 27 of 67

Question 27

MediumOriginal question

Which of these is a solution of $x\frac{dy}{dx} + y = 0$ ?

y = x

Correct answerYour answer

y = e^{- x}

Correct answerYour answer

y = \frac{1}{x}

Correct answerYour answer

y = - x

Correct answerYour answer

Show the answer and explanation

CorrectNot quiteAnswer C

Correct answer: C

Try $y = \frac{1}{x}$ : $y' = - \frac{1}{x^{2}}$ .
Substituting makes both sides equal for every $x$ ; each of the others leaves something over.

Ten questions from Differential Equations, at your own pace.

Ten questions from Differential Equations, at your own pace.