1 Answers

# Find the value of x for which the function y = x³ – x has a minimum value…

QuizTablet Community!

##### Admin

**Find the value of x for which the function y = x³ – x has a minimum value**

**A.**** ****√3/3**

**B.**** ****√3**

**C.**** ****– √3/3**

**D.**** ****– √3**

**QUICK ANSWER…**

**A**

**DETAILS…**

**We would have to differentiate y = x****³**** – x and make x the subject of the formula.**

**dy/dx = 3x****³ ¯ ¹ – 1x¹ ¯ ¹**

**dy/dx = 3x² – 1**

**the minimum value will the point at which dy/dx = 0**

**so, 3x² – 1 = 0**

**3x² = 1**

**x² = 1/3**

**x = √1/3**

**x = 1/√3**

**rationalizing,**

**x = 1/√3 × √3/√3**

**x = √3/3**

**Now for the right answer to the above question:**

**Option A is correct.****Option B is incorrect.****C is not correct.****D is not the correct answer.**

**KEY-POINTS…**

**You may please note these/this:**

**A function is minimum or maximum only at a point where dy/dx = 0.****So, for questions like this, you would have to firstly differentiate the function, and then equate the answer to 0.****If you love our answers, you can login to comment and say hi to us at the comment section…**

**To raise new related question****s, c****lick the ASK A QUESTION BOTTON down this page…**

**/ culled from 2020 JAMB-UTME mathematics past question 39 /**

##### Find the value of x for which the function y = x³ - x has a minimum value... » QuizTablet

MATHS SHORT-CLASS!!!

**Course Provider: **
Organization

**Course Provider Name: **
N.D Sammy

**Course Provider URL: **
QuizTablet.com

**Editor's Rating:**

8